I have read several articles and published posts recently about whether an employee has a right to refuse to answer questions in an investigation being conducted by an employer in circumstances in which to do so might expose the employee to punishment such as dismissal. Some of those writers have asserted that the common law principle which excuses a person from being required to answer questions which might incriminate him or her, most commonly encountered in criminal law, is alive and well in the context of employment situations.
I am not so sure.
The starting point is that at common law there is a principle to the effect that a person is not required to answer questions the answers to which may expose the person to criminal jeopardy.
The relevant privilege was described by members of the High Court of Australia in Petty v The Queen  HCA 34; 173 CLR 95 in the following terms at 99 per Mason CJ, Deane, Toohey and McHugh JJ:
“A person who believes on reasonable grounds that he or she is suspected of having been a party to an offence is entitled to remain silent when questioned or asked to supply information by any person in authority about the occurrence of an offence, the identity of the participants and the roles which they played. That is a fundamental rule of the common law which, subject to some specific statutory modifications, is applied in the administration of the criminal law in this country. An incident of that right of silence is that no adverse inference can be drawn against an accused person by reason of his or her failure to answer such questions or to provide such information. To draw such an adverse inference would be to erode the right of silence or to render it valueless.”
It is at once apparent that the principle applies to the application of criminal law.
In Baff v New South Wales Commissioner of Police (2013) NSWSC 1205 Adamson J pointed out that there are several takes on the principle.
“The immunities referred to by Lord Mustill at 30-31 of R v Director of Serious Fraud Office are:
(1) a general immunity, possessed by all persons and bodies, from being compelled on pain of punishment to answer questions posed by other persons or bodies;
(2) a general immunity, possessed by all persons and bodies, from being compelled on pain of punishment to answer questions the answers to which may incriminate them;
(3) a specific immunity, possessed by all persons under suspicion of criminal responsibility whilst being interviewed by police officers or others in similar positions of authority, from being compelled on pain of punishment to answer questions of any kind;
(4) a specific immunity, possessed by accused persons undergoing trial, from being compelled to give evidence, and from being compelled to answer questions put to them in the dock;
(5) a specific immunity possessed by persons who have been charged with a criminal offence, from having questions material to the offence addressed to them by police officers or persons in a similar position of authority;
(6) a specific immunity (at least in certain circumstances, which it is unnecessary to explore), possessed by accused persons undergoing trial, from having adverse comment made on any failure (a) to answer questions before the trial, or (b) to give evidence at the trial.”
In the end, Justice Adamson concluded that a member of the police in New South Wales was not required to answer questions put to him in a workplace investigation which had the potential to incriminate him, and summarized his decision thus
“Requiring the accused to answer questions about the subject matter of a pending charge prejudices the accused in his or her defence of the pending charge (whatever answer is given). Even if the answer cannot be used in any way at the trial, any admission made in the examination will hinder, even prevent, the accused from challenging at trial that aspect of the prosecution case. And what would otherwise be a wholly accusatorial process, in which the accused may choose to offer no account of events, but simply test the sufficiency of the prosecution evidence, is radically altered. An alteration of that kind is not made by a statute cast in general terms. If an alteration of that kind is to be made, it must be made by express words or necessary intendment.”
But do any of these principles apply to an investigation being conducted by an employer, especially in circumstances in which the employer’s policies mandate that employees do so? I doubt it.