22 In Hammond, the relevant issue concerned the juxtaposition of the privilege against self-incrimination and the effect of s 6DD of the Royal Commissions Act 1902 (Cth), which provided that a statement or disclosure made by a person in the course of giving evidence before a Royal Commission was not admissible in evidence against that person in any civil or criminal proceedings, other than proceedings for an offence against the Royal Commission Act. Gibbs CJ, with whom Mason J and Murphy J relevantly agreed, said:
It was common ground that if the plaintiff were again examined at the inquiry he would be bound to answer questions designed to establish that he committed the offence with which he is charged, and that his objection on the ground that his answers might incriminate him would not constitute a defence to a prosecution for failing to answer the questions.
. . . .
Once it is accepted that the plaintiff will be bound, on pain of punishment, to answer questions designed to establish that he is guilty of the offence with which he is charged, it seems to me inescapably to follow, in the circumstances of this case, that there is a real risk that the administration of justice will be interfered with. It is clear that the questions will be put and pressed. It is true that the examination will take place in private, and that the answers may not be used at the criminal trial. Nevertheless, the fact that the plaintiff has been examined, in detail, as to the circumstances of the alleged offence, is very likely to prejudice him in his defence.