Just as prime minister Mackenzie King was about to leave his office to attend the opening of the 20th Parliament he received a secret communiqué from the undersecretary of state for external affairs, Norman Robertson. Robertson told King that a clerk at the Russian Embassy in Ottawa, named Igor Gouzenko, had called upon the office of the minister of justice, Louis St. Laurent, and had stated that he had stolen documents from the vault in the embassy that disclosed a very serious threat to the security of Canada.

King then managed to keep the Gouzenko revelations secret for five months. Without warning, on Feb. 4, 1946, an American radio station revealed that King had told American president Harry Truman of a Soviet spy ring in Canada. Only then did King inform his cabinet and set up a royal commission. Opposition leaders were informed of the developments on Feb. 14. The next morning at 7 a.m., 12 arrests were made, including three National Research Council employees, an employee of the Munitions and Supplies Department and a clerk at External Affairs.

The Russian spy network which Gouzenko detailed had also infiltrated the Bank of Canada and McGill University. Worse, Fred Rose (Cartier), the only Communist Party member of Parliament, was identified as a Soviet recruitment agent. Rose went into hiding but was arrested on March 14.

On March 18, 1946, King stunned Canadians when he read sparse parts of the report of the secret royal commission into Hansard: "A network of undercover agents has been organized for the purposes of obtaining secret information from employees of departments of the dominion government. These operations were carried on by certain members of the staff of the Soviet embassy at Ottawa under direct instructions from Moscow."

William Lyon Mackenzie King - Prime Minister (Glengarry): I need scarcely say that these paragraphs describe as serious a situation as has existed in Canada at any time. Igor Gouzenko was a cipher clerk in the Russian Embassy, associated with the military attaché. Apparently he left the embassy around six-thirty in the evening of the day prior to the one at which he went to call at the office of the minister of justice. He left with the papers in his possession and went from the embassy to one of the newspaper offices in this city. It was to the Ottawa Journal that he went and told his story to one of the persons whom he found in the office. He wanted to see the editor. The editor was not present. Though his story seemed fantastic, he was told that he should go and see the Mounted Police.

He went back to his house that night (4-511 Somerset St. West). Next morning, he came to the office of the minister of justice. He had his wife and little child with him. Then, at night, he went to his home and asked neighbors if they would be kind enough to look after his little child. He was fearful that something might happen to him that night. He felt that by this time it would have been discovered that he had left the embassy and had taken with him papers of significance, and that he might expect to be killed in the course of the evening unless he got protection. The persons in whom he confided his situation took him into their apartment along with the child and had them all stay in one of the rooms. Meantime, the gentleman in whose apartment it was went to the city police. Arrangements were made with the police to be in the near vicinity lest there should be any incidents.

About midnight, his apartment was entered by four people. The four persons were from the Russian Embassy. The city police wanted to know from them just why they were there. They claimed immunity, being members of the embassy. No arrests were made. They were allowed to return to the embassy.

Gouzenko asked the city police if they could put him in contact with the Royal Canadian Mounted Police. He was taken to the mounted police and he gave a full statement, producing the documents that he had, and asking for protection for his life and the lives of his wife and child.

King omitted large portions of sensitive information in his sensational report to Parliament. The Soviets were spying through Canada for intelligence on the American atomic weapons program. Incredibly, at the offices of the Ottawa Journal, Gouzenko had twice pleaded to speak to the editor. One reporter rudely ignored him exclaiming, "I'm busy," forfeiting one of the biggest stories of Canadian journalism. King himself did not initially believe Gouzenko. He admitted in Parliament that his first reaction was that Gouzenko "should be told to go back to the embassy with the papers he had in his possession." Any doubts about King's judgment were laid to rest when he added that, "I did think of going to Russia myself and of speaking to General Stalin. What I know of Stalin causes me to believe that he would not countenance action of this kind on the part of officials of his country."

A jury in Montreal sentenced Fred Rose to six years for conspiracy to give unauthorized information to the Soviet Union. On Jan. 30, 1947, King moved that because Rose was incapable of sitting or voting in the House, a new writ be issued for Cartier. There were no objections.

Gouzenko, who had been the Crown's star witness against Rose, risked his secret identity by constantly courting the media. He quickly became a thorn in the side of a succession of Canadian governments. In 1968, he even published and personally distributed a pamphlet which described Pierre Trudeau as a "potential Canadian Castro." Embroiled in controversy since his defection, Gouzenko died in 1982.