8.—The Commission or a Committee shall not investigate a complaint made or referred to it unless the identity of the person making the complaint is disclosed to it. Where, having regard to all the circumstances, the Commission or a Committee considers it appropriate to do so, it may restrict the disclosure of such identity to those to whom knowledge of it is necessary or expedient for the purposes or by reason of the investigation of the compliant by the Commission or the Committee, as the case may be, or otherwise in the interests of justice.