Learn more about Igor GouzenkoJanuary 13, 1919, Rogachev, Soviet Union – June 25, 1982, Mississauga, Canada) was a cipher clerk for the Soviet Embassy to Canada in Ottawa, Ontario. He defected on September 5, 1945 with 109 documents on Soviet espionage activities in the West.
Gouzenko's defection exposed Joseph Stalin's efforts to steal nuclear secrets, and the then-unknown technique of planting sleeper agents. With World War II over, the "Gouzenko Affair" helped change western perceptions of the Soviet Union from an ally to an enemy, and is often credited as a triggering event of the Cold War. 
Gouzenko was born in Belorussia. At the start of the World War II, he joined the military where he trained as a cipher clerk. In 1943, he was stationed in Ottawa, where for two years he coded and deciphered incoming and outgoing messages for the GRU. His position as cipher clerk gave him access to Soviet espionage activities in the West.
In 1945, hearing that he and his family were to be sent home to the Soviet Union and dissatisfied with the quality of life and the politics of his homeland, he decided to defect. Gouzenko walked out of the Embassy door carrying with him a briefcase with Soviet code books and decyphering materials. He initially went to the Royal Canadian Mounted Police, but the RCMP officers on duty refused to believe his story. He then went to the Ottawa Journal newspaper, but the paper's night editor was not interested, and suggested he go to the justice ministry, where nobody was on duty. Terrified that the Soviets had discovered his duplicity, he went back to his apartment and hid his family in the apartment across the hall for the night. Gouzenko, hidden by a neighbour, watched through the keyhole as a group of Soviet agents broke into his apartment and began searching through his belongings and only left when confronted by Ottawa police.
The next day Gouzenko was able to find contacts in the RCMP who were willing to examine the evidence he had removed from the Soviet embassy. Gouzenko was transported by the RCMP to the secret "Camp X", now abandoned, but located in present-day Oshawa and comfortably distant from Ottawa. Camp X had been used during World War II as a training station for Allied undercover personnel. While there, Gouzenko was interviewed by investigators from Britain's MI5 (because Canada is part of the British Commonwealth, Britain's internal Security Service was employed, not MI6, which would have been the case for a defector outside the British Empire), and also by investigators from the American FBI (the Central Intelligence Agency was in the process of being formed and was not yet operational).
Even once the RCMP expressed interest in Gouzenko, it has been alleged that the Canadian Prime Minister William Lyon Mackenzie King initially wanted nothing to do with him. Even with Gouzenko in hiding and under RCMP protection, King reportedly pushed for a diplomatic solution to avoid upsetting the Soviet Union, still a wartime ally and ostensible friend. Documents reveal that King, then 70 and weary from six years of war leadership, was aghast when Norman Robertson, his undersecretary for external affairs, and his assistant, Hume Wrong, informed him on the morning of September 6, 1945 that a "terrible thing" had happened. Gouzenko and his wife Anna, they told him, had appeared at the office of Justice Minister Louis St. Laurent with documents unmasking Soviet perfidy on Canadian soil. "It was like a bomb on top of everything else", King wrote.
Robertson told the Prime Minister that Gouzenko was threatening suicide, but King was adamant that his government not get involved, even if Gouzenko was apprehended by Soviet authorities. Fortunately for Gouzenko, Robertson ignored the Prime Minister's wishes, and authorized granting asylum to Gouzenko and his family, on the basis that their lives were in danger.
 Ramifications of the defection
The evidence provided by Gouzenko led to the arrest in Canada of a total of 39 suspects, of which 18 were eventually convicted, including Fred Rose, the only Communist Member of Parliament in the Canadian House of Commons and Sam Carr, the Communist Party's national organizer. A Royal Commission of Inquiry, headed by Justice Robert Taschereau and Justice Roy Kellock was conducted into the Gouzenko Affair and his evidence of a Soviet spy ring in Canada. It also alerted other countries around the world, such as the United States and the United Kingdom, that Soviet agents had almost certainly infiltrated their nations as well.
Gouzenko provided many vital leads which assisted greatly with ongoing espionage investigations in Britain and North America. His testimony is believed to have been vital in the successful prosecution of Klaus Fuchs, the German communist physicist, who emigrated to Britain and who later stole atomic secrets for the Soviets. Fuchs spent some time at Chalk River, northwest of Ottawa, where atomic research has been underway since the early 1940s. His information also likely helped in the Rosenberg investigation in the U.S. Gouzenko, being a cipher clerk by profession, likely also assisted with the Venona investigation, which probed Soviet codes and which eventually led to the discovery of vital Soviet spies such as Donald Maclean, Guy Burgess, Kim Philby, Anthony Blunt, and John Cairncross (the so-called Cambridge Five), as well as Alan Nunn May.
 Life in Canada
Gouzenko and his family were given another identity by the Canadian government out of fear of Soviet reprisals. Little is known about his life afterwards, but it is understood that he settled down to a middle class existence somewhere in Canada. Gouzenko managed to keep in the public eye, however, writing two books, This Was My Choice a non-fiction account of his defection, and a novel The Fall of a Titan which won a Governor General's Award in 1954. Gouzenko also appeared occasionally on television, always with a white cloth draped over his head.
Gouzenko died of a heart attack in 1982 and his grave was not initially marked. His wife Svetlana, who died in September 2001, was buried next to him and it was only in 2002 that the family put up a headstone.