Igor Sergeyevich Gouzenko (Russian: Игорь Сергеевич Гузенко [ˈiɡərʲ sʲɪrˈɡʲejɪvʲɪdʑ ɡʊˈzʲenkə]; January 26, 1919 – June 25, 1982) was a cipher clerk for the Soviet embassy to Canada in Ottawa, Ontario, and a lieutenant of the GRU (Main Intelligence Directorate). He defected on September 5, 1945, three days after the end of World War II, with 109 documents on the USSR's espionage activities in the West. This forced Canada's Prime Minister Mackenzie King to call a Royal Commission to investigate espionage in Canada.