A former detainee of Guantanamo Bay is taking legal action against the Canadian government over its alleged role in his 14 years behind bars marked by torture and intimidation.

Mohamedou Ould Slahi, a Mauritanian who lived in Montreal for two months, launched a $35-million lawsuit Friday alleging that faulty intelligence provided by Canadian authorities contributed to his detention at the U.S. offshore military prison, where he said he suffered fierce beatings, sleep deprivation and sexual assault.

A statement of claim from Slahi, whose story became a best-selling memoir and Hollywood film, states that surveillance by Canada's spy agency and police force was fed to his American interrogators. Eventually their "torture broke him down" and prompted a false confession about a plan to blow up the CN Tower, which he had never heard of, the court filings state.

Slahi, now a 51-year-old writer-in-residence at a Dutch theatre company, left Canada in 2000 after authorities with the Canadian Security Intelligence Service and the RCMP started questioning him about supposed ties to Ahmed Ressam, the so-called millennium bomber who planned to attack Los Angeles airport. The two had briefly had attended the same large mosque in Montreal.

The Federal Court of Canada ruled in 2009 that Slahi, who was once a permanent resident, was not entitled to intelligence documents because he was neither a citizen nor subject to legal proceedings in Canada.

The Attorney General of Canada has not yet filed a response to the allegations against CSIS and the RCMP, which did not immediately reply to requests for comment.

Mustafa Farooq, head of the National Council of Canadian Muslims, said Canada's alleged complicity in the torture of a Canadian resident stems from Islamophobic stereotypes, and that accountability is needed.

"The reality is that Mr. Mohamedou was in peril in part because he happened to be praying at a mosque, where he was at the wrong place in the wrong time and happened to come under the surveillance of the Canadian state," Farooq said in a phone interview.

"Part of the reason that it's so horrifying is that the Canadian government and Canadian national security administrations participated in having a man who had done nothing wrong tortured, that we knew about it, and that we tried to make sure Canadians never found out about it."

Farooq drew comparisons to the cases of Maher Arar and Omar Khadr.

Arar, a Syrian-born Canadian, was detained in New York in September 2002 and shipped abroad by U.S. authorities, ending up in a dungeon-like Damascus prison. Under torture, he gave false confessions about involvement with al-Qaida. He agreed to a $10.5-million settlement and accepted an apology from then-prime minister Stephen Harper for "any role Canadian officials may have played" in the affair.

The case of Omar Khadr, a Canadian citizen who at the age of 15 was detained at Guantanamo Bay for 10 years for the wartime killing of a U.S. army sergeant in Afghanistan, culminated in a $10.5-million court settlement with the federal government in 2018.

This report by The Canadian Press was first published April 23, 2022.