in Tofilau v The Queen (2007) 231 CLR 396, [28]:
There are three separate, but overlapping, inquiries that may be made in deciding whether evidence of an out-of-court confessional statement is admissible.
First, there is the question, commonly decided as a question of ‘voluntariness’ presented when the confession in issue was made to someone identified as a ‘person in authority'
Second, there may be the consideration of exclusion of the evidence of the confession based upon notions of ‘basal voluntariness’.
Finally, there is the discretion to exclude evidence of the confession for reasons of fairness, reliability, probative value or public policy