(1) In a criminal proceeding for a serious indictable offence, such unfavourable inferences may be drawn as appear proper from evidence that, during official questioning in relation to the offence, the defendant failed or refused to mention a fact:
(a) that the defendant could reasonably have been expected to mention in the circumstances existing at the time, and
(b) that is relied on in his or her defence in that proceeding.
Subsection (1) does not apply unless:
(a) a special caution was given to the defendant by an investigating official who, at the time the caution was given, had reasonable cause to suspect that the defendant had committed the serious indictable offence, and
(b) the special caution was given before the failure or refusal to mention the fact, and
(c) the special caution was given in the presence of an Australian legal practitioner who was acting for the defendant at that time, and
(d) the defendant had, before the failure or refusal to mention the fact, been allowed a reasonable opportunity to consult with that Australian legal practitioner, in the absence of the investigating official, about the general nature and effect of special cautions.
It is not necessary that a particular form of words be used in giving a special caution. An investigating official must not give a special caution to a person being questioned in relation to an offence unless satisfied that the offence is a serious indictable offence.