A GRU cipher clerk based at the Soviet embassy in Ottawa, Canada, Gouzenko defected in September 1945 and delivered 109 documents from the referentura to the Royal Canadian Mounted Police (RCMP) identifying a large number of GRU spies active in Canada. A royal commission was appointed to review the documents, cross-examine Gouzenko, and take evidence from the suspected spies, and its report was subsequently published.
Seventeen members of the exposed GRU network were prosecuted, of whom nine were convicted of espionage. Gouzenko, his wife, and children were resettled in Canada and occasionally made public appearances to defend themselves from criticism. With help from his RCMP interpreter, he wrote Fall of a Titan and his wife published Before Igor, and their story was turned into a movie.