What Ireland involves is no simple question of ensuring fairness to an accused but instead the weighing against each other of two competing requirements of public policy, thereby seeking to resolve the apparent conflict between the desirable goal of bringing to conviction the wrongdoer and the undesirable effect of curial approval, or even encouragement, being given to the unlawful conduct of those whose task it is to enforce the law. This being the aim of the discretionary process called for by Ireland it follows that it by no means takes as its central point the question of unfairness to the accused. It is, on the contrary, concerned with broader questions of high public policy, unfairness to the accused being only one factor which, if present, will play its part in the whole process of consideration.
As that passage makes plain, the principal considerations of "high public policy" which favour exclusion of evidence procured by unlawful conduct on the part of investigating police transcend any question of unfairness to the particular accused. In their forefront is the threat which calculated disregard of the law by those empowered to enforce it represents to the legal structure of our society and the integrity of the administration of criminal justice. It is the duty of the courts to be vigilant to ensure that unlawful conduct on the part of the police is not encouraged by an appearance of judicial acquiescence. In some circumstances, the discharge of that duty requires the discretionary exclusion, in the public interest, of evidence obtained by such unlawful conduct. In part, this is necessary to prevent statements of judicial disapproval appearing hollow and insincere in a context where curial advantage is seen to be obtained from the unlawful conduct. In part it is necessary to ensure that the courts are not themselves demeaned by the uncontrolled use of the fruits of illegality in the judicial process. As Stephen and Aickin JJ. went on to point out [24] , there are cases in which the question of unfairness to the particular accused does not play any significant part at all. In such cases, it "is not fair play that is called in question but rather society's right to insist that those who enforce the law themselves respect it A discretion exercisable according to the principles in Ireland's Case serves this end whereas one concerned with fairness may often have little relevance to the question" [24] . Ultimately, the question whether evidence of an incriminating statement procured by unlawful conduct on the part of investigating police should be excluded on grounds of public policy must be resolved by a balancing process. In that balancing of policy considerations, the relevance and importance of fairness or unfairness to the particular accused will depend upon the circumstances of the particular case [25] .
1. (1978) 141 C.L.R., at pp. 74-75.
2. (1978) 141 C.L.R., at p. 75.
3. (1978) 141 C.L.R., at p. 75.
4. ibid., at p. 77; and see Cleland v. The Queen (1982), 151 C.L.R., at pp. 24, 36.