What is the privilege against self-incrimination in regulatory investigations?

The privilege against self-incrimination is the right of an individual to refuse to answer any question, or to produce any document or thing, if to do so 'may tend to bring him into the peril and possibility of being convicted as a criminal'.1

The privilege against self-incrimination is 'a basic and substantive common law right, and not just a rule of evidence'.2 Subject to any statutory modification, that common law right is available:

  • to persons suspected of a crime (e.g. a criminal defendant or potential defendant);3
  • to persons questioned in civil proceedings (e.g. an individual giving evidence in court proceedings for regulatory offences);4 and
  • in non-curial contexts (e.g. regulatory and workplace investigations).5

The privilege against self-incrimination is related to the principle that, in a criminal trial, the prosecution must prove its case unassisted by the accused defendant. As summarised further in our article " Understanding the playing field", this principle is a fundamental aspect of our accusatorial system of criminal justice.

What is the right to silence?

The privilege against self-incrimination relates to, but differs from, the 'right to silence'. In Australia, the privilege against self-incrimination does not hold absolute and there is 'no free-standing or general right of a person charged with a criminal offence to remain silent.'6

The right to silence protects an individual from being required to testify against oneself (whether or not that testimony is incriminating). It is akin to the right created by the Fifth Amendment to the Constitution of the United States (i.e. to 'plead the fifth'). The privilege against self-incrimination protects the right not to be made to incriminate oneself.

The difference, in practice

While these rights have a common-law history, the Uniform Evidence Law provides a good example of each. For example:

  • Section 128 of the Evidence Act 1995 (Cth) creates a statutory privilege against self-incrimination. It provides an avenue for a witness to object to giving particular evidence if that evidence 'may tend to prove that the witness (a) has committed an offence against or arising under an Australian law or a law of a foreign country or (b) is liable to a civil penalty';
  • Section 17 of the Evidence Act 1995 (Cth) creates a statutory right to silence. It provides that a 'defendant is not competent to give evidence as a witness for the prosecution'. It applies only in criminal proceedings and means that a defendant cannot be required to give evidence at their own trial. However, a defendant may choose to give evidence in their own defence. In practice, it only applies to individuals (including officers of corporations).

The Uniform Evidence Laws are relevant to proceedings in a court. They do not regulate the powers of regulators seeking or compelling information in the course of an investigation.

Application to external/regulatory investigations

Individuals can assert the privilege against self-incrimination in investigations conducted by a regulator.

However, despite the history and fundamental importance of the privilege against self-incrimination, the right can be modified or abrogated by clear legislative intent.7 This occurs where the public interest outweighs 'the interests of the individual in order to enable the true facts to be ascertained.'8

Whether or not the privilege is modified or abrogated in a regulatory investigation will depend on the scope of the relevant regulator's powers and the legislative scheme in which they operate.

In some cases, the privilege against self-incrimination can be exercised to permit an individual to refuse to answer questions or provide information that the individual may otherwise be compelled to provide a regulator.9

In other cases, the privilege against self-incrimination is modified so that an individual is required to answer questions or provide information, even if it would tend to incriminate that person, but that information cannot be used as evidence against that individual.10

The inability to use any such evidence against an individual is known as a 'use immunity'. Depending on the legislative regime, it may be necessary to claim privilege in order to attract the 'use immunity'. At other times a 'use immunity' is granted automatically.

Regulators that can pierce the privilege against self-incrimination include the Australian Tax Office (ATO), Australian Securities and Investments Commission (ASIC), the Australian Competition and Consumer Commission (ACCC), and the Australian Criminal Intelligence Commission (ACIC).

Application to workplace investigations

A basic feature of the employer-employee relationship is that employees must comply with lawful and reasonable directions relating to their employment issued by their employer. This generally includes cooperation with investigations conducted by, or on behalf of, an employer.11

But can an employee exercise a right to the privilege against self-incrimination in a workplace investigation and in short, yes, and this can have serious practical implications for internal investigations into corporate and other misconduct.

In 2011, Errol Baff, a police officer with the NSW Police Force (NSWPF), was involved in an incident in which his gun discharged and injured a member of the public. An internal investigation was commenced. The Commissioner of the NSWPF directed Constable Baff to attend a 'non-criminal departmental interview' to answer questions. The police officer invoked the privilege against self-incrimination and refused to comply with the Commissioner's direction.

The Supreme Court of NSW held that Constable Baff was entitled to refuse to answer questions concerning the incident and that any order directing Constable Baff to answer questions would not be lawful. In coming to that conclusion, the Court held that there was no clear intention in the Police Act 1990 (NSW) to abrogate the common law right to claim privilege against self incrimination as it applied to police officers under internal investigation.


1 Sorby v Commonwealth (1983) 152 CLR 281, 288.

2 Reid v Howard (1995) 184 CLR 1, [8].

3 Petty & Maiden v R (1991) 173 CLR 95.

4 Reid v Howard (1995) 184 CLR 1, [15].

5 Griffin v Pantzer (2004) 137 FCR 209, [44].

6 Lee v New South Wales Crime Commission (2013) 251 CLR 196.

7 Environment Protection Authority v Caltex Refining Co Pty Ltd (1993) 178 CLR 477, 503 (Mason CJ and Toohey J).

8 Environment Protection Authority v Caltex Refining Co Pty Ltd (1993) 178 CLR 477, 503 (Mason CJ and Toohey J). See also Sorby v Commonwealth (1983) 152 CLR 281, 298 (Gibbs CJ); Rees v Kratzman (1965) 116 CLR 63, 80 (Windeyer J).

9 See, for example, Petroleum and Gas (Production and Safety) Act 2004 (Qld), s 762

10 See, for example, Australian Securities and Investments Commission Act 2001 (Cth), Competition and Consumer Act 2010 (Cth) ss 133D, 135B, 151BUF, 155B; s 68(3); Proceeds of Crime Act 2002 (Cth), s 39A; Independent Commission Against Corruption Act 1988 (NSW), s 37; Work Health and Safety Act 2011 (NSW), s 172.

11 R v Darling Island Stevedoring & Lighterage Co Ltd; Ex parte Halliday (1938) 60 CLR 601, 621–622.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.