According to If applied in the United States, what is the most obvious legally functional difference between the British and American "mirandizing" phrase? and the answers to that question, it may be against your best interest to stay silent when being questioned by the police in the U.K.
Is this the same in Australia, a former Commonwealth colony? Or is the system closer to that of the U.S.?
The right to silence is a fundamental part of Australian common law in every jurisdiction. But it is not a Constitutional right in any jurisdiction so it can be overridden by clear and explicit statute law.
An important limitation of the rule is that it only applies to natural persons, so it cannot be invoked in an investigation against a corporation.
The general rule is that a judge cannot instruct a jury to draw an adverse inference against a defendant if they use their right to silence (Petty v R 1991 HCA 34) but there are exceptions. Most notably, where the case relies entirely on circumstantial evidence which only the defendant can testify about (Weissensteiner v R 1983 HCA 65), although Victoria has abolished this exception.
In addition, Petty v R held that it was permissible to draw inferences if the defendant answered certain questions but declined to answer others. So, if you are going to invoke your right, do it completely.
In NSW, s89A of the Evidence Act (NSW) allows adverse inferences to be drawn from a failure to mention something which the subject later relies upon in Court and which he/she ought reasonably have been aware of at the time of the questioning. However, they must have been warned of this and they must have a lawyer physically present at the time of the questioning.
In practice, studies have shown that only 5-10% of suspects who are subsequently committed for trial on serious indictable offences invoke their right to silence.
