Every so often, a case comes up that reminds us of an often forgotten undertaking that solicitors owe the court: the "Harman" undertaking.

The Harman undertaking concerns documents or information that the court compels third parties to produce. It operates to prevent any of the parties to litigation from using documents obtained in the course of that litigation for the purpose of other unrelated proceedings, without the leave of the court.

Generally, the court will look for special circumstances explaining why a document should be released for use in other proceedings. Even when special circumstances are established, the court still has discretion regarding whether to authorise the release of the information.

In general, the courts do not readily release parties from the Harman undertaking, and the matter of NSW Mobile Fleet Services Pty Limited v Max Mobile & Detailing Pty Limited [2023] NSWSC 140 is an example of where leave was not given.

In this case, documents were obtained under subpoenas issued to third parties - including a government department. Two emails that were produced were sought to be disclosed, so as to bring their contents to the attention of the Independent Commission Against Corruption.

Whilst it is not difficult to establish that special circumstances exist, the matter then becomes one of the proper exercise of the court's discretion, to which many factors are relevant. Such factors include the attitude of the author of the document and any prejudice they may sustain, and importantly - the likely contribution of the document to achieving justice in the second proceedings.

For example, in the well-publicised case of Ashby v Slipper (No 2) [2016] FCA 550, concerning a former Speaker of the House of Representatives, the Harman undertaking was relaxed so that disclosure of certain official information contained in the Speaker's diary could be investigated by the Australian Federal Police.

In the recent matter of NSW Mobile Fleet Services Pty Limited v Max Mobile & Detailing Pty Limited [2023] NSWSC 140, there was public interest relating to the possible misuse of public office by the author of the emails, and the legitimate interest in investigating that. The implied breach of public trust satisfied the requirement of special circumstances.

But that was not the end of the matter. The judge looked at whether the material justified the suspicion. The seriousness of the allegations demanded that there should be a strong foundation for drawing the inference of a breach of public trust, and his honour was not satisfied that there was.

Secondly, given the possible prejudice to the author of the email, the court refused to allow the emails to be used in separate litigation.

In conclusion - cases concerning the Harman undertaking do not often arise, so NSW Mobile Fleet Services Pty Limited v Max Mobile & Detailing Pty Limited [2023] NSWSC 140 serves as a useful reminder to practitioners that documents obtained in the course of one set of proceedings cannot be used for purposes outside those proceedings without the court's permission, and the court will not readily relax the Harman undertaking.

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.