Can counsel for the respondent rely upon the common law rule of secrecy which would reveal the identity of a police informant?

Counsel for the respondent relies upon the common law rule of secrecy which prohibits the disclosure of information which would reveal the identity of a police informant. The scope of this rule was discussed by Beetz J. in Bisaillon v. Keable et al.(1983), 1983 CanLII 26 (SCC), 7 C.C.C. (3d) 385 at pp. 411-2, 2 D.L.R. (4th) 193 at pp. 219-20, 51 N.R. 81 at p. 121 (S.C.C.): It follows from these reasons that at common law the secrecy rule regarding police informers' identify has chiefly taken the form of rules of evidence based on the public interest, which prohibit judicial disclosure of police informers' identity by peace officers who have learned the informers' identity in the course of their duties. A witness also may not be compelled to state whether he is himself a police informer. The rule was developed in criminal proceedings, apparently in trials for high treason, but it also applies in civil matters, and in both cases it has been established for reasons which relate to the essential effectiveness of the criminal law. The rule is subject to only one exception, imposed by the need to demonstrate the innocence of an accused person. There are no exceptions in proceedings other than criminal. Its application does not depend on the judge's discretion, as it is a legal rule of public order by which the judge is bound. Any alteration of this common law rule must be done by way of statute in clear and explicit terms. No such statutory provision has been enacted. On the contrary, the rule seems to have been codified in s. 22(1)(b)(ii) of the Privacy Act with the modification that the discretion to refuse to disclose that type of information lies with the head of the government institution. On an application for review under s. 41, s. 49 empowers the court to determine whether the head of the institution had reasonable grounds on which to refuse to disclose the personal information. As I have already stated, however, that exemption should have been specifically identified by the respondent in the notice of refusal.