The privilege against self-incrimination is an important protection provided by the common law, with significant practical implications. It’s something all lawyers need to know about.
In a nutshell: The privilege against self-incrimination allows a person to refuse to answer a question, or to produce any document, if doing so would tend to expose them to conviction for a crime, or a civil penalty.
Beneath that simple proposition lies an iceberg of detail and nuance.
In this article, I focus on the 10 most important things you need to know about the privilege.
The privilege is a creation of the common law, but it is recognised and regulated to some degree by statute.
In Queensland, the privilege is expressly recognised by s10 of the Evidence Act 1977 (Qld), which Forbes has describes as a “terse affirmation of the common law privilege”.1
Queensland’s Evidence Act makes only minor alterations to the operation of the privilege in practice, for instance by preventing an accused from relying on it where they choose to testify at their own trial (s10(2)). Otherwise, though, the content of the privilege is still provided for by the common law.
In jurisdictions with one of the Uniform Evidence Acts (such as the Commonwealth’s Evidence Act 1995), a statutory form of the privilege is found in s 128. However, the broad principles are the same.
The privilege arises not only in relation to the commission of a crime, but in respect of all forms of ‘civil penalty’.
It’s usually easy enough to identify provisions which impose criminal liability. But what is a civil penalty?
At common law it may be understood as a is punishment imposed on proof of an offence for which the burden of proof is only on the civil standard of a balance of probabilities.
Under the Uniform Evidence Acts, “a person is taken to be liable to a civil penalty, if in an Australian or overseas proceeding (other than a criminal proceeding), the person would be liable to a penalty arising under Australian law or a law of a foreign country”.
Importantly, a civil penalty is not just any civil liability. The fact you may have committed a tort, or breached a contract, will not enable you to rely on the privilege in answer to a question.
However, lawyers should be aware that an exposure to liability for a crime or civil penalty may arise in varied and unexpected contexts. For example, in Police Service Board v Morris,the High Court found that the privilege could prima facie arise to allow a police officer to refuse to answer questions tending to show the commission by them of disciplinary offences (under the Police Regulation Act 1958 (Vic)), within the context of an inquiry conducted the employer.2
For the privilege to arise, there must be a “real and appreciable danger” in respect of the crime or civil penalty.
This classic formulation of the test was set down by Cockburn CJ in the English case of R v Boyes, where it was said that:3
“[T]he danger to be apprehended must be real and appreciable, with reference to the ordinary operation of law in the ordinary course of things – not a danger of an imaginary or unsubstantial character ..”
Described elsewhere, there must be a “real risk as opposed to a remote possibility”.4
The privilege doesn’t only arise in respect of questions asked of a witness.
Historically, the privilege most clearly arose in the context of a witness giving oral evidence. As Brennan J put it in Environment Protection Authority v Caltex Refining Co Pty Ltd,the privilege provides a “a shield against conviction by testimony wrung out of the mouth of the offender.”5
However, modern case law indicates the privilege applies at all stages of litigation, and more broadly than Brennan J’s observation might otherwise indicate.
As Forbes observes: “the common law privilege covers self-incrimination in any form, including vica voce evidence, affidavits, evidence on commission and responses to subpoenas or applications for discovery and inspection”.6
There is also case law indicating the privilege can arise in relation to a requirement to produce documents. For instance, as Allsop J (as his Honour then was) observed in Griffin v Panzter,7 the privilege enables a person to “not answer questions or produce documents”.
However, as the ALRC has observed, where the privilege arises in relation to documents, “it only excuses the person from producing them. If the documents are, for example, seized under a warrant, they are not protected by the privilege.”8
The privilege is not limited to courts. It can be claimed in other contexts as well.
As McHugh J observed in Environment Protection Authority v Caltex Refining Co Pty Ltd:9
“It is a general privilege which, absent a contrary legislative indication, may be invoked outside the course of judicial proceedings whenever a person is asked to answer questions or provide information which may tend to expose that person to a penalty.”
For example, in Pyneboard Pty Ltd v Trade Practices Commission, the High Court accepted the privilege could arise in respect of hearings before the Trade Practices Commission.10
Another demonstration of the breadth the privilege is it may arise within the context of an employment relationship. As the Full Federal Court observed in Grant v BHP Coal Pty Ltd:11
“It is established that privilege against self-incrimination is capable of applying in respect of questions asked of an employee by an employer”.
The privilege is personal.
The privilege can only be claimed by a person concerned about the prospect of incriminating themselves, and not some other person. For instance, it can’t be claimed on behalf of a person’s spouse, friend, co-worker, or employer.12
Another implication of the privilege being personal is an individual may choose to waive it; for instance, by proceeding to answer the questions, or produce the requested documents.
Finally, it’s important to note the privilege only arises for ‘natural persons’. The High Court has confirmed that it cannot be claimed by corporations.13
It is for a person asserting the privilege to raise it, and to identify its precise basis.
At common law, there is no duty on a judge to advise a witness of the privilege against self-incrimination, even assuming that they can see that an answer is likely to incriminate them.
For that reason, it is incumbent on lawyers to make sure their clients know the privilege exists (recognising that it is for the client alone to decide whether to claim it).
In practice, judges often warn a witness who is about to enter the ‘danger zone’. However, sometimes the risk is not apparent. Cross-examination often moves quickly, and a witness may let the cat out of the bag before they, or anyone else, is cognisant of the implications.
In comparison, in jurisdictions with a Uniform Evidence Act, s132 requires a Court to ensure a witness who may have a right to object is informed of the effect of the privilege.
Having claimed the privilege, there must be sufficient evidence or submissions in support of the claim. The privilege is not established by mere assertion.14
Where the privilege arises, the evidentiary effect is as if the question had never been asked.
In theory at least, nothing should be made of the fact that a person has invoked the privilege. As the Queensland Benchbook notes, “the general thrust of authority is to the effect that no adverse inference is available.”15 In a trial involving a jury, a jury will often be directed to this effect.
However, invoking the privilege is, in practical terms, likely to result in a jury, judge, or other decision-maker, inferring the witness has something to hide. It is impossible to prevent them reaching this view.
For that reason, important considerations of strategy may be at play when a witness is deciding whether or not to claim the privilege. That is a matter on which a lawyer may need to advise.
The privilege is not immune from statutory abrogation.
Parliaments have, on many occasions, considered the public interest in a complete answer – or provision of required documents – outweighs the interest of individuals in maintaining the privilege.
For example, s190 of the Crime and Crime and Corruption Act 2001 (Qld) excludes reliance on the privilege for questions put by a presiding officer at a hearing of the CCC. There is a similar provision in 14(1A) of the Commissions of Inquiry Act 1950 (Qld).
However, whether any particular provision abrogates the privilege needs to be assessed on a case-by-case basis. In that context, the ‘principle of legality’ provides a presumption against abrogation of the privilege. As Kiefel J (as her Honour then was) said in X7 v Australian Crime Commission:16
“[A] statutory intention to abrogate or restrict a fundamental freedom or principle or to depart from the general system of law must be expressed with irresistible clearness.”
However, abrogation may sometimes be implied. One example is Nugent v Stewart (Commissioner of Police), where the Queensland Court of Appeal confirmed that, for the purposes of police discipline, self-incrimination privilege was impliedly abrogated by provisions in the Police Service Administration Act 1990 (Qld).17
Whether the privilege has been impliedly excluded in any particular case is likely, of course, to be open to argument.
At common law, courts have no power to grant an immunity in return for an answer (or disclosure). But a number of statutes have provided for this.
At common law, if you claim the privilege and the claim is upheld, that’s the end of the matter – you are not required to answer the question, or provide the disclosure. However, statutes sometimes compel an answer in exchange for a ‘use immunity’.
One example is section 14A(1) of the Commissions of Inquiry Act 1950 (Qld), which provides that a person may be ordered to give evidence about a matter and is not entitled to remain silent. However, subject to certain exceptions, statements or disclosures made in answer are not admissible in evidence against the person in any civil or criminal proceedings.
A ‘use immunity’ which commonly arises in practice is provided by s128 of the Uniform Evidence Acts (such as the Evidence Act 1995 (Cth), as applicable in Federal Court proceedings). That provision allows a judge to override a witnesses’ claim for privilege in certain circumstances, provided they are satisfied that the “interests of justice” require the evidence to be given.
In exchange, a witness will be given a certificate which will prevent their testimony being used against them in “any proceeding in an Australian court”.
However, the immunity provided by s 128 does not mean that a witness is completely free of consequence for their answers or disclosures. It does not, for example, prevent them being subject to discipline by their employer, the subject of criminal investigation, or even criminal prosecution based on other evidence, but in respect of the same offence as disclosed.
Finally, it’s important to know the power (and immunity) afforded by s 128 is only provided to courts which are “required to apply the laws of evidence”.18 That means that it does not arise in some tribunals and quasi-judicial bodies, such as the Fair Work Commission.19
1 JRS Forbes, Evidence Law in Queensland (Thomson Reuters, 13th edition, 2021).
2 (1985) 156 CLR 397.
3 (1861) 121 ER 730, 738.
4 Sorby v Commonwealth (1983) 152 CLR 281, 289-90.
5 (1993) 178 CLR 477, 514.
6 JRS Forbes, Evidence Law in Queensland (Thomson Reuters, 13th edition, 2021).
7 (2004) 137 FCR 209, .
8 Australian Law Reform Commission, Traditional Rights and Freedoms (ALRC Report 129) <https://www.alrc.gov.au/publication/traditional-rights-and-freedoms-encroachments-by-commonwealth-laws-alrc-report-129/11-privilege-against-self-incrimination/a-common-law-right-10/>.
9 (1993) 178 CLR 477, 547.
10 (1983) 152 CLR 328.
11  FCAFC 42, .
12 Meneses v Directed Electronic OE Pty Ltd  FCAFC 190, .
13 Environment Protection Authority v Caltex Refining Co Pty Ltd (1993) 178 CLR 477.
14 Grant v BHP Coal Pty Ltd  FCAFC 42, .
15 Queensland Benchbook, ‘Privilege Against Self-Incrimination’ <https://www.courts.qld.gov.au/__data/assets/pdf_file/0007/86047/sd-bb-47-privilege-against-self-incrimination.pdf>.
16 (2013) 248 CLR 92, .
17  QCA 223.
18 That is because of the legislative definitions, under the Uniform Evidence Acts, of “Court” (as used in s 128).
19 Fair Work Act 2009 (Cth) s 591 provides that the Fair Work Commission is not bound by the rules of evidence.
William Isdale is a barrister with a broad civil practice, focusing on commercial and regulatory matters. He has contributed several articles in a previous role as a Senior Legal Officer at the Australian Law Reform Commission.