s 21 Protection of informers
21.—(1) Except as provided in this section, no complaint as to an offence under Part 2 is to be admitted in evidence in any civil or criminal proceedings, and no witness in the proceedings is to be obliged or permitted to disclose the name or address of any informer in respect of the offence, or state any matter which might lead to the discovery of the informer. (2) If any article or document which is in evidence or liable to inspection in the civil or criminal proceedings contains any thing that names or describes the informer or is likely to lead to the discovery of the informer, the court hearing the proceedings must cause that thing to be concealed from view or to be obliterated so far as may be necessary to protect the informer from discovery. (3) A court may order the production of a complaint, or require or permit the full disclosure concerning an informer, in respect of an offence under Part 2, if —(a) in any proceedings for the offence, the court, after full inquiry into the case, is of the opinion that the informer wilfully made a material statement which the informer knew or believed to be false or did not believe to be true; or (b) in any other proceedings, the court is of the opinion that justice cannot be fully done between the parties in the proceedings without the discovery of the informer. (4) In this section, a reference to an offence under Part 2 includes a reference to an abetment of, or a conspiracy or an attempt to commit, the offence.