121.—(1) Subject to this section, no witness in any civil or criminal proceedings is obliged or permitted to disclose the name or address of an informer or the substance of the information received from the informer or to state any matter which might lead to the informer’s discovery.
(2) If any books, documents or papers which are in evidence or liable to inspection in any civil or criminal proceedings contain any entry in which any informer is named or described or which might lead to the informer’s discovery, the court is to cause all such passages to be concealed from view or to be obliterated so far only as may be necessary to protect the informer from discovery.
(3) If, on the trial for any offence under this Act, the court, after full inquiry into the case, believes that the informer wilfully made in the informer’s complaint a material statement which the informer knew or believed to be false or did not believe to be true, or if in any other proceedings the court is of the opinion that justice cannot be fully done between the parties to the proceedings without the discovery of the informer, it is lawful for the court to require the production of the original complaint, if in writing, and permit inquiry, and require full disclosure, concerning the informer.