Substance, Procedure, And Proof: Unpacking The Supreme Court’s Judgment In Katagum v. Umar & Anor. And Its Effect On Witness Statements On Oath Improperly Sworn Or Signed

1. Introduction

Modern legal practice has long evolved beyond witnesses testifying fully in court for their evidence-in-chief.² To save valuable judicial time by expediting proceedings, and to enhance the due administration of justice, witnesses in civil proceedings now adopt their pre-prepared written statements at trial. Under various court rules, these witnesses’ written statements are expected to be made on oath and filed alongside the originating processes.³ Failure to do this has been held to be a fundamental error.⁴ The laid-down rule and procedure for taking an oath is that the deponent physically appears before the oath-administering authority, usually the Commissioner for Oaths (“the Commissioner”) at the court’s registry, to take the oath.⁵ However, it is common practice, dictated by the need for convenience and flexibility, for deponents to sign their statements not in the presence of the Commissioner, and for the signed statements to be subsequently taken before the Commissioner for his endorsement. This practice is quite irregular. The question is, what is the effect of this irregularity on the affected witness statement and the evidence based on such witness statement?

This article attempts to answer this question in view of seemingly conflicting decisions of the courts, with a focus on the recent decision of the Supreme Court in the case of Katagum v. Umar & Anor. (“Katagum’s Case”).⁶

2.              The Previous Regime

Before Katagum’s Case,⁷ the position of the law on evidence based on an irregular witness statement on oath was quite convoluted. The rule appeared to be well-laid that evidence  based  on  a  fundamentally  defective  witness  statement  must  be discountenanced. The Court of Appeal made this point in the case of Okobiemen v. UBN Plc,⁸ as follows:

Where therefore as in the instant appeal case, the witness’s evidence in chief (Dw2), her evidence under cross-examination and re-examination if any, are founded on a fundamentally defective witness’s statement on Oath, it is as if the witness gave no evidence at all. The case of UAC v. Macfoy (1962) A.C. 152 is instructive: You cannot place something on nothing and expect it to stand. Therefore, the statement on oath of DW2 is incompetent hence evidence proffered by her at the trial go to no avail. The trial court also lack jurisdiction to act on those pieces of evidence drawn from DW2. See: Gundiri v. Nyako (2012) NSCQLR (Pt. 1) page 26, (2014) 2 NWLR (Pt. 1391) 211. The entire evidence derived from DW2 including the written statement adopted and relied on by her lack of probative value hence same ought to have been ignored. Issue No.1 is resolved in favour of the appellant.⁹

This principle was subsequently adopted by the Supreme Court in the latter case of Abubakar v. INEC.¹⁰

Consequently, the important question that needed to be resolved was what amounted to a fundamental defect in a witness statement. Whilst the authorities were settled on the fundamental nature of certain defects, they were not always consistent on whether failure to swear to and sign a witness statement before the Commissioner, as the administering officer, amounted to a fundamental defect capable of avoiding it and the oral evidence based on it. For example, there seemed to be no dispute that the following defects were fundamental:

1. Deposing to a witness statement by proxy and adopting the same in court;¹¹
2. Adopting the English translation of a witness deposition made other than in the English language.¹² This was held to be tantamount to adopting a statement made by another;
3. Deposing to a witness statement before the deponent’s legal practitioner who is ordinarily authorised to administer an oath;¹³ and
4. Adopting a witness statement not deposed to before any authorised officer.¹⁴

Appellate courts in Nigeria have issued conflicting decisions regarding witness statements not signed in the presence of the Commissioner. Although legally required to be executed before the Commissioner, a common irregular practice involves deponents signing independently, with the Commissioner later endorsing the document to falsely imply formal compliance. This normalized irregularity forms the central focus of this paper. In the case of Chidubem v. Ekenna>,¹⁵ the Court of Appeal held that failure to swear and sign a witness statement before the authorised person renders the statement defective. In the words of Kekere-Ekun, JCA (now CJN):

From the evidence of these witnesses, it is clear that none of them signed their depositions before the person authorized to administer oaths. The attempt by learned counsel for the appellants to draw a distinction between signing a deposition and swearing an oath, is in my humble view, merely splitting hairs. The requirement of the law is that the deposition on oath must be signed in the presence of the person authorized to administer oaths. The two acts are part of the same transaction… I therefore hold that the lower Tribunal was correct when it discountenanced the written depositions of PW3, PW4, PW5 and PW6 for non-compliance with Section 90(f) of the Evidence Act and paragraph 1(1) (b) of the Practice Directions.¹⁶

The Supreme Court arrived at the same conclusion as the Court of Appeal in the subsequent cases of Buhari v. INEC¹⁷ and Nammagi v. Akote,¹⁸ where evidence tendered by a witness was discountenanced after the witness declared: “I signed the witness statement on oath before my lawyer.” It was immaterial whether the statement was meant to be signed before the lawyer as a Notary Public authorised to administer oaths, or whether it was meant to be signed before the Commissioner for Oaths. This position was re-echoed in the more recent Court of Appeal decision in Mata v. Kano State Public Complaints & Anti-Corruption Commission & Anor.,¹⁹ where Honourable Justice Ita George Mbaba, JCA, made a very instructive pronouncement thus:

The law is that fraud vitiates whatever is erected on it… I think it amounts to fraud, lies or dishonesty, to procure statement on oath (or document) purportedly deposed to or sworn before a Commissioner for Oaths (or before a Magistrate, Judge or Notary Public), when the same (statement, on oath or document) was not signed or thumbprinted before the appropriate administering authority. That defeats the whole essence of the law governing affidavit/oath evidence as stipulated in Sections 5, 10, and 12 of the Oaths Act. This was dutifully discussed and analysed in the case of Erokwu Vs Erokwu (2016) LPELR- 41515 CA by my lord Ogunwumiju, JCA (as she then was - now JSC).… I had cause to adopt and rely on her reasoning in the case of Abdul-Rahim Ya'u Vs Ministry of Land and Physical Planning, Kano & Ors (2022) LPELR - 58781 (CA)… In ASHIRU VS INEC & ORS (2020) 16 NWLR (PT. 1751) 416 AT 441, it was said by Eko, J.S.C. that: “The law is that the depositions on oath must be signed by the deponent in the presence of the person authorised to administer Oaths, failing which the deposition on oath must be discountenanced.” I do not think the reasonings in the case of Udeagha & Anor Vs Omegara & Ors (2010) 11 NWLR (Pt. 1204) 168, and Mohammed Vs APC & Ors: CA/K/137/2019 delivered on 18/4/2019, are applicable to this case/Appeal, as the PW2 had clearly stated (albeit innocently): “I am the one who signed my statement on oath in the office of my Counsel.” The above confession has put a lie to all the official imprimatur of the Commissioner for Oath, in the statement of oath by PW2, suggesting that the same was sworn before him (Commissioner for Oath).²⁰

Hence, by these authorities, which repeatedly reference one another, this defect was considered a fundamental defect that affected the substance of the statement, not merely the form, which would have been excusable. In each case, the consequence of the finding was dire – all evidence, oral and documentary, drawing life from the fundamentally defective statement was expunged. It did not end at that. The pleadings in support of which the evidence was led were also deemed abandoned, having been left bereft of evidence. This point was made in Buhari v. INEC²¹ in the following words:

If evidence is not led on a fact pleaded in either the petition or the reply, the fact will be deemed to have been abandoned unless the fact was admitted by the adverse party. This is because pleadings have no mouth to talk and need human being with mouth and sense to articulate them in court. This principle of law will not apply where the particular pleading is admitted.²²

Turning to the other side of the coin, there were authorities to the effect that the subsequent adoption of the irregular witness statement in open court cures any defect relating to the taking of the oath before an appropriate officer. In Udeagha v. Omegara,²³ the Court of Appeal asserted this point, which was confirmed by the Court in the case of Nwogu v. SCOA (Nig) Ltd.²⁴ This contrary position is based on making a necessary distinction between a witness statement on oath and an affidavit and the categorisation of the arguments to the contrary as technical arguments. In Udeagha v Omegara,²⁵ His Lordship held:

Statement (sic) of witnesses which are adopted during oral evidence on oath are different from mere affidavit evidence which stand on their own without backup, and which are not subjected to cross examination. It is such affidavit evidence which do not meet the requirements of Section 90 of the Evidence Act that are intrinsically inadmissible. Where a witness is in Court to say that he/she is adopting an irregular written deposition, the implication is that the witness is re-asserting on oath what is contained in the irregular deposition, such adoption makes all the evidence in the written deposition admissible. This is quite different from where the deposition had not been adopted in the open Court.²⁶

In Nwogu v. SCOA (Nig) Ltd.,²⁷ the Court held:

…this later oath cures any defect in the previous oath and therefore it will be too technical to reject an oath on grounds of defect even when the maker is in Court having taken an oath before the Court. The rehearsal cannot be the real thing. A dream is a dream different from reality. The written deposition is like a rehearsal while the evidence in Court is the real thing. Mistakes done in the rehearsal or in training are corrected in the real situation. The point I am laboring to make here is that affidavit and written depositions on oath are different and not the same in terms of legal importance and consequence… I find it a very technical argument and it is common knowledge that our law has no room for technicality anymore as substantial justice is what is craved for now. See RALPH UWA ZURUIKE & ORS VS. A.G. FEDERATION NSCQR VOL. 53 2013 PAGE 236. In the circumstance, I resolve issue 3, which is the first issue I am addressing in favour of the Respondent. In other words, I am not expunging the evidence of DW2 from the records.²⁸

The courts were very inconsistent on the issue, as can be seen from both sets of cases which basically overruled one another until, at least, the Supreme Court’s decision in Nammagi v. Akote²⁹ in 2021. One may wonder why the Court of Appeal decisions that support the latter position did not take into account the 2008 decision of the Supreme Court in Buhari v. INEC.³⁰ The likely explanation is that the decision was never brought to the court’s attention at the time the judgments were delivered. This explains why Ogunwunmiju, JCA (as she then was), later departed from her position in Udeagha v. Omegara³¹ in favour of the former position in the subsequent case of Erokwu v. Erokwu,³² where she cited and relied on Buhari v. INEC.³³ Therefore, it is safe to say that the reigning position under this regime was that where a witness signed his witness statement at any place other than before the Commissioner, and the statement was afterwards taken to the Commissioner for signing and stamping, such a statement was fundamentally defective and any evidence based on the same was liable to be expunged.

THE NEW REGIME: KATAGUM’S CASE

Decided on 16^th January 2026, Katagum’s Case represents the extant position of the law. It favours the latter position above, as it follows the trail of the likes of Udeagha v. Omegara and Nwogu v. SCOA (Nig.) Ltd. and distinguished Buhari v. INEC. In this case, the Supreme Court was presented with the issue, “whether or not the lower Court was right in expunging the evidence of PW1, on the ground that it was signed in his lawyer’s office.” This was a typical scenario of a witness swearing to and signing his witness written statement, meant to be sworn before the Commissioner, in his lawyer’s office. The Supreme Court, allowing the appeal, held that the Court of Appeal was wrong to have upheld the objection to the evidence that emanated from PW1 and expunged the same on the ground that PW1 signed his witness statement in his lawyer’s office. By this latest decision of the Apex Court on this topic, it follows therefore that evidence based on a witness statement signed other than in the presence of the Commissioner is valid. The rationale for the court’s decision is examined below.

3.              Ratio Decidendi in Katagum’s Case and Commentaries

Some of the principles that undergird the decision in Katagum’s Case, as well as this writer’s commentaries, are highlighted below:

3.1           Distinction Between Witness Written Statement and Affidavit

The Supreme Court, relying on the Court of Appeal case of Okpa v. Irek & Anor.,³⁴ made a fundamental distinction between a witness written statement and an affidavit. Importantly, the court held that while a written statement is merely a statement that becomes evidence only when adopted by the witness in court, an affidavit is evidence ab initio. Hence, the former should not be held to be as sacrosanct as the latter, which may not be tested under cross-examination.³⁵ This distinction implies that a witness statement, not being evidence, is excluded from the scope/application of the Evidence Act. Therefore, the rule that an affidavit be sworn before an authorised person, as well as other rules relating to affidavit evidence under the Evidence Act, does not apply to a witness statement.³⁶

3.2           Mere Irregularity

Leveraging on the above distinction and relying on its previous decision in Adejugbe

1. Aduloju,³⁷ the Supreme Court applied the provisions of section 4(2)(c) of the Oaths Act to hold that where a witness signs a witness statement before his lawyer as against the Commissioner, that is merely an irregularity which does not render inadmissible the evidence based on the witness statement. The oath taken by the witness in open court supersedes, regularises, and/or cures any defect in the statement.³⁸

3.3           Distinction Between Witness Written Statement and Oral Evidence

The Supreme Court also distinguished between a written statement and oral evidence given in court:

When a witness in open Court takes oath as a witness and adopts his or her written statement of relevant facts sworn or not sworn, the written statement ceases to exist as a witness written statement and transforms into the witness’ oral evidence in examination in chief upon which the witness can be cross-examined. This admitted oral evidence on oath cannot be expunged as evidence on the ground of any defect in the written witness statement precedent to it.³⁹

Basically, the Apex Court is saying that a written statement is just a statement of the evidence that a witness wishes to give in court, and once the witness adopts that statement as his evidence-in-chief, the evidence exists differently from the statement, and any grouse against the statement cannot affect the evidence it transformed into.

3.4          Time of Objection 

The law is trite that where there is an irregularity, an aggrieved party must object to the irregularity timeously at the time of its occurrence. Failure to do this bars the party from complaining about the irregularity later in the proceedings or on appeal, except where there has been a miscarriage of justice.⁴⁰ Based on this principle, the Supreme Court decided that the proper time to object to the regularity of the statement on oath of PW1 and draw the attention of the Court to the said irregularity was at the point PW1 sought to adopt the same as his evidence. The Respondent did not make this objection; proceeded to cross-examine PW1; and relied on the evidence in his Written Address. These numerous steps amounted to a condonation of the irregularity.

However, a question that needs to be asked regarding this point is: what would be the relevance of an objection raised before the written statement is adopted? The witness cannot be cross-examined as to the circumstances surrounding the preparation of his statement if he has not adopted the same as his evidence-in-chief. Additionally, the court had made the point that the statement, even if not sworn at all, could be adopted by the witness.⁴¹ Hence, it is the deferential view of this writer that any objection raised at this point would as well be of no moment. This, indeed, has a far-reaching effect on the various rules of courts that provide that the witness statements be made on oath.

3.5           Unpleaded Facts

It is the law that evidence adduced in support of facts not pleaded goes to no issue and ought to be disregarded by the court. This rule applies to both evidence-in-chief and evidence elicited in cross-examination; they must be supported by the pleadings of the parties. In this case, the Supreme Court made this point and observed that the fact that PW1 signed his written deposition in his lawyer’s office was not pleaded in any of the pleadings in the case. Consequently, the evidence of such fact, elicited during cross-examination, goes to no issue.

3.6           Prevalence of Documentary “Evidence”

In light of the endorsement of the Commissioner that the PW1 swore to his witness statement at the Registry of the High Court of the Federal Capital Territory, Abuja, before him, is the contention that PW1 signed the statement in his lawyer’s office, as admitted by him under cross-examination, relevant? The Supreme Court answered this question in the negative. According to the Learned Justices, the statement of the Commissioner, who administered the oath, being “unchallenged,” any contention to the contrary was of no moment.⁴²

While this point may lack much relevance in the big picture, it is the view of this writer that the endorsement of the Commissioner could not really have carried any weight because the witness statement, as pointed out by the Supreme Court, is not evidence. Had it been evidence, then it could be argued that, as documentary evidence, it supersedes any contrary evidence elicited from the witness in cross-examination. It is therefore not clear how the Supreme Court expected this mere statement to have been challenged if the evidence of the witness himself was not sufficient.

3.7           Relevance of Distinguishing Buhari v. INEC

The Supreme Court faulted the Court of Appeal’s reliance on the case of Buhari v. INEC on the ground that the case was decided on facts distinct from the facts in Katagum’s Case. The Court clarified that its decision to expunge the evidence in Buhari v. INEC was predicated on the fact that the witness statement on which the evidence was based was not merely signed before the lawyer to the witness as in the instant case, but the lawyer was also the administrator of the oath as a Notary Public. This distinction now appears superfluous. In the Court of Appeal’s perspective, both practices amounted to fundamental defects, while the Supreme Court felt only the latter is a fundamental defect. However, this distinction no longer appears relevant in the face of the sweeping decision in Katagum’s Case that a witness statement is not evidence and that it can be adopted even if not sworn at all?

4.              The Process/Procedure for Making a Deposition on Oath

Beyond the common practice, and for whatever it is worth, the procedure for making a deposition on oath was highlighted in Erokwu v. Erokwu.⁴³ The procedure ideally involves the following processes:

1. The deponent making a statement in writing;
2. The document is taken to a Commissioner for Oaths or any person duly authorised to take the oath;
3. The Commissioner for Oaths requires the deponent to swear on a holy book particular to the deponent’s faith or a mere declaration for a deponent who has no religious affiliation or whose faith forbids the deponent to swear;
4. The Commissioner for Oaths then asks the deponent to verify what has been stated; and
5. The deponent afterwards signs in the presence of the Commissioner for Oaths who witnesses that the Affidavit was sworn to in his/her presence.

5.              Conclusion

Katagum’s Case untied the legal Gordian Knot when it decided that where a witness signs a witness statement before his lawyer as against the Commissioner, that is merely an irregularity which does not render inadmissible the evidence based on the witness statement. The oath taken by the witness in open court supersedes, regularises, and/or cures any defect in the statement. This reasoning indubitably appeals to the justice of a case and heralds a progressive phase in trial advocacy in Nigeria.

Although it has been said that no Judge has ever written a perfect judgment or ruling such that no mistake or fault can be found in or with it when put or placed under a judicial microscope, it is however the duty of every Judge to do substantial justice in each case.⁴⁴ It is the view of this author that the decision in Katagum’s Case is good law and has resolved the uncertainties that lingered in judicial corridors in Nigeria for decades. It provided the Supreme Court with the golden opportunity to re-emphasise the need for the courts to prioritise substantial justice over technicalities.

Nonetheless, litigants, lawyers, persons authorised to administer oaths, and other stakeholders in the justice sector, are advised to ensure compliance with the laid-down procedure when making any form of deposition to avoid unnecessary objections in court and the risks that may be associated with non-compliance.

Footnotes

1 Ahmad Dasuki, Associate, Dispute Resolution Department, SPA Ajibade & Co., Lagos, Nigeria.

2  Before the introduction of the frontloading system in Nigeria, witnesses testified completely orally in court during their evidence-in-chief, a process known as viva voce testimony. Rather than relying on pre-filed written statements, lawyers led their witnesses through direct questioning in the Witness Box to narrate the entire story and tender documents sequentially.

3        See, Order 5 Rule 1(2) of the High Court of Lagos State (Civil Procedure) Rules 2019.

4  See, Okobiemen v. U.B.N. Plc (2019) 4 NWLR (Pt. 1662) 265 at pp. 276, paras. F – H; 277, para. B.

5        See, s 6 of the Oaths Act 1963. See also, Ashiru v. I.N.E.C. (2020) 16 NWLR (Pt. 1751) 416.

6        (2026) LPELR – 83085 (SC).

7        Ibid.

8        (2019) 4 NWLR (Pt. 1662) 265 (CA).

9        Ibid. at p. 277, paras. E – F, per Hussaini, JCA (emphasis added).

10      (2022) 8 NWLR (Pt. 1833) 463. See also, Ashiru v. INEC (n 5); and Buhari v. INEC (2008) 4 NWLR

(Pt. 1078) 546.

11      See, Ashiru v. I.N.E.C. (n 5) at p. 477, para. H; and 488, para. A.

12      See, Gundiri v. Nyako (2014) 2 NWLR (Pt. 1391) 211; and Abubakar v. INEC, supra.

13  See, Buhari v. INEC, (n 10). This was based on section 83 of the Evidence Act, Cap. E14, Laws of the Federation of Nigeria, 2004 (now section 112 of the Evidence Act 2011 [as amended]), which provides that, “an affidavit shall not be admitted which is proved to have been sworn before a person on whose behalf the same is offered, or before his legal practitioner, or before a partner or clerk of his legal practitioner.”

14  See, Okobiemen v. UBN Plc, (n 4) at p. 277, para. B.

15 (2008) LPELR – 3913 (CA). See also, the following cases: Dr. Muhammed Ibrahim Onujabe v. Fatimah Idris (2011) LPELR – 4059 (CA); Erokwu v. Erokwu (2016) LPELR – 41515 (CA) and Abdul-Rahim Ya'u v. Ministry of Land and Physical Planning, Kano & Ors. (2022) LPELR – 58781 (CA).

16      Ibid. at p. 16, paras. C – G; and 17, paras. A – C (emphasis added).

17      See, (n 10).

18      (2021) 3 NWLR (Pt. 1762) 170 at p. 195, paras. G – H.

19      (2023) LPELR – 60503 (CA).

20      Ibid., at pp. 19 – 34, paras. F – A (emphasis added).

21      See, (n 10).

22      Ibid., per Niki-Tobi, JSC (of blessed memory) at p. 413, para. A.

23      (2010) 11 NWLR (Pt. 1204) (CA).

24      (2018) LPELR – 49785 (CA).

25      See, (n 23).

26      Ibid., per Ogunwumiju, JCA (as he then was) at pp. 19 – 25, paras. B – D (emphasis added).

27      See, (n 24).

28      Ibid., per Ebiowei Tobi, JCA at pp. 23 – 25 (emphasis added).

29      Supra.

30      See, (n 10).

31      See, (n 23).

32      (2016) LPELR – 41515 CA.

33      See, (n 10).

34      (2012) LPELR – 8033 (CA) at pp. 9 – 10, para. B.

35      See, Katagum’s Case (n 6) at p. 47, para. A.

36      The Supreme Court, per Onnoghen, JSC, collapsed this distinction in Buhari v. INEC.

37      (2022) 3 NWLR (Pt.1816) 131 (SC).

38      See, Katagum’s Case (n 6) at p. 49, paras. D – E.

39      Ibid., Honourable Justice Agim, JSC, at pp. 41 – 42 (emphasis added).

40      See, Ekwuruekwu v. State (2020) 4 NWLR (Pt. 1713) 114.

41      See, Katagum’s Case (n 6) at pp. 41 – 42.

42      Ibid., at p. 43. paras. F – G.

43      See, (n 32), per Ogunwunmiju, JCA, at pp. 18 and 19.

44      See, Isyaku & Ors. v. Ibrahim Master & Ors. (2002) LPELR – 7060 (CA) at pp. 11 – 31, paras. C – D, per Honourable Justice Adamu, JCA.

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