Recent public interest immunity cases give useful guidance for government entities who may be contemplating a claim in the future.

Document production in litigation presents many challenges. For public agencies, there can be an additional problem: while disclosing documents might be in a party's interests, it might not be in the public interest.

Public agencies can make a claim of public interest immunity in respect of such documents, but this is a complex area of law. Two recent Victorian cases, and the approach taken by the successful agency, Victoria Police, give helpful guidance to all government entities who may be contemplating a claim in the future (Ryan v State of Victoria [2015] VSCA 353; Dupont v Chief Commissioner of Police (2015) 295 FLR 283).

Public interest immunity: A short recap

Public interest immunity is a common law doctrine replicated in the Uniform Evidence Acts. It operates to relieve government litigants from producing evidence where:

  • the evidence relates to matters of state; and
  • the public interest in its disclosure in the legal proceeding is outweighed by the public interest in preserving the secrecy or confidentiality of that evidence.

What is considered a “matter of state” is not closed. For example, claims can be made where production of the evidence may:

  • prejudice the prevention, investigation or prosecution of offences;
  • disclose (or enable the disclosure of) the identity of confidential sources of information relating to the enforcement or administration of laws;
  • prejudice national security, defence or international relations of Australia; or
  • otherwise prejudice the proper functioning of government.

In light of the conflicting principles of open justice, courts will closely scrutinise all public interest immunity claims. “Public interest immunity will not be lightly conferred and it should not be lightly claimed” (Holloway v Commonwealth [2016] VSC 317).

What documents were sought in Ryan and Dupont?

In Ryan, the plaintiff brought proceedings for alleged assault and battery in relation to an altercation he had with a troop horse of the Victoria Police Mounted Branch. He sought the Mounted Branch’s training material, which was resisted on the basis that public disclosure of this material could impair the efficacy of future Mounted Branch operations, and enable the public to neutralise the tactics of the Mounted Branch.

In Dupont, a litigant issued a subpoena to Victoria Police requiring the production of documents relating to an internal investigation of a complaint made against a police officer. Victoria Police argued that production would undermine its complaints and investigation procedures - the free exchange of information would be compromised if police officers participating in investigations understood that their involvement had the potential to become public.

Balancing the competing public interests

A broad range of matters will affect whether or not the public interest in preserving secrecy or confidentiality of the documents in question outweighs the interest of production in the proceeding.

The importance of the documents or information to the proceeding will be a critical consideration. Other matters include:

  • the extent to which the documents are already in the public domain;
  • the nature of the subject matter of the proceedings;
  • the currency of the documents or information contained within them;
  • whether there are alternative sources of the information available; and
  • the means available to limit publication in the proceeding.

The first threshold issue: are the documents relevant?

Leaving aside these factors – all evidence in proceedings must nonetheless be shown to be relevant to facts in issue prior to being admitted. This raises the question: how does the Court assess relevance generally, and the importance of the documents in the proceeding, when weighing up the competing public interests?

The Court in Ryan has clarified that both concepts are interrelated and should be considered together. The relevance of the documents is likely to be determinative of the importance of the documents.

The plaintiff in Ryan was not alleging negligence or a failure to meet a standard of conduct found in a training manual, and the training manuals were not relied upon to make out a defence. Accordingly, the training manuals were not relevant facts in issue, and Victoria Police’s claim was upheld primarily on this basis.

The second threshold issue: establishing a sufficient public interest

If the matter can be said to be relevant and potentially important, then the Court will consider whether the claimed public interest in maintaining confidentiality or secrecy in the documents in question is sufficient. This requires affidavit material from the public agency explaining why the documents in question are sensitive.

In Dupont, it was said that human resources procedures (ie. investigations) should not be entitled to public immunity. In response, Victoria Police led evidence from a senior superintendent to explain internal investigations procedures, the role of confidentiality in that process, and the likely risk to investigations if that confidentiality was compromised. The superintendent testified that the assurance of confidentiality in internal investigations was vital in assisting the free flow of information from complainants and witnesses.

The Court held that this provided ample evidence for the conclusion the immunity should attach to the investigation documentation.

Lessons for government agencies claiming public interest immunity

Ryan and Dupont provide very useful guidance for all government entities on the practical considerations bearing upon a public interest immunity claim. As can be seen:

  • The relevance and importance of the documents should be considered at the outset. A careful assessment of the pleadings and all issues in dispute is required.
  • If a decision has been made to claim the privilege, then the nature of the confidentiality or secrecy needs to be identified with rigour and precision. As inDupont, supporting evidence should be given by a senior official who has detailed experience with the disputed documents, who can cogently demonstrate the currency and sensitivity of the information at hand.