Canada’s top spy agency destroyed a cache of secret Cold War-era files on former Prime Minister Pierre Trudeau, a Soviet sympathizer who visited Fidel Castro and is the father of Canada’s current Prime Minister Justin Trudeau.

Pierre Trudeau in 1970. (AP File Photo)

Historians called the destruction of the documents “outrageous” and a “a crime against Canadian history,” according to the Canadian Press, which first reported the revelation.

The secret dossier on Pierre Trudeau was compiled by the the RCMP Security Service, a now-defunct arm of the Royal Canadian Mounted Police. The files were later transferred to the Canadian Security Intelligence Service, which destroyed them in 1989.

Under Canadian law, security files on an individual become open to the public 20 years after a person’s death. Trudeau died in 2000, meaning his records would have been publicly available as early as next year.

Trudeau served as prime minister from 1968 to 1979 and from 1980 to 1984. His outreach to communist governments in Russia, China, and Cuba created tension between Canada and the United States.

In 1976, Trudeau became the first NATO leader to visit communist Cuba, where he proclaimed to an audience: “Viva Castro!”

Prior to becoming prime minister, Trudeau also traveled to the Soviet Union under Josef Stalin and China under Mao Zedong.