Watch your words: The admissibility of evidence from Royal Commissions in civil and criminal proceedings

Royal Commission witnesses beware! Answers, information, or documents given by a person to a Royal Commission could be admissible in a broader scope of proceedings, following the decision in Re Mokbel (No 2) [2024] VSC 39.

In the first decision to consider section 40(1) of the Inquiries Act 2014 (Vic) (the "use immunity"), Justice Fullerton has held it does not prevent the use of information or evidence given by a witness during a Royal Commission to cross-examine that witness in a proceeding to which they are not personally a party.

The use immunity rule in Victorian Royal Commissions

The use immunity provides that any answers, information, or documents given by a person to a Royal Commission is not admissible in evidence, or able to be used, "against the person" in any other proceedings (with certain exceptions). The use immunity serves to counterbalance the extensive powers of a Royal Commission to acquire information, and the inroads that Act makes into various privileges. Significantly, section 33 provides that the privilege against self-incrimination does not apply where a person is required to provide information to a Royal Commission.

Mr Mokbel sought to use evidence given by police officers to the Royal Commission into the Management of Police Informers (RCMPI) to challenge the credibility of those same police officers when they appeared as witnesses in a related proceeding. None of those police officers were a party to the proceeding.

The issue between the parties was whether the use immunity operated to prohibit the use of those police officers' evidence in that way. That is, whether using evidence given by a witness to the RCMPI to undermine that same witness' credibility, amounted to using that evidence "against the person".

Mr Mokbel's and the DPP's competing arguments about use immunity

Mr Mokbel argued that the use immunity was confined to where the evidence is sought to be used "against the person" to establish their legal liability in civil or criminal proceedings, or in proceedings where their legal rights are infringed. Where the information was not going to be used to establish the liability of the witnesses, Mr Mokbel argued the use immunity should not apply.

The Director of Public Prosecutions (DPP) contended that the word "against" should be given its natural and ordinary meaning, which included use that was unfavourable or to a person's detriment:

"any cross-examination of a witness in these proceedings on the basis that they have made a prior inconsistent statement to the [RCMPI] would be to use that material against that person… irrespective of the fact that they are not a party to these proceedings and irrespective of the fact that these proceedings are not concerned with their criminal or civil liability.”

How far does the use immunity stretch?

Justice Fullerton accepted Mr Mokbel's arguments, and found the use immunity did not prohibit Mr Mokbel from using evidence given at the RCMPI to challenge the credibility of witnesses.

Her Honour accepted the use immunity should be read beneficially to protect those who give evidence in Royal Commissions, and should not be narrowly construed. However, her Honour found there was nothing to suggest the use immunity was intended to extend to a witness compelled to give evidence in proceedings where, in the course of giving evidence, what they said before a Royal Commission might be used in an adverse way, or have the potential to be treated as adverse to them.

Justice Fullerton also considered the DPP's interpretation of the use immunity could undermine the administration of criminal justice more broadly, as it would allow a witness in a criminal or civil proceeding to give deliberately false evidence without fear of contradiction, despite having given conflicting evidence to a Royal Commission.