A Canadian man jailed in Mauritania for his alleged links to a terrorist group has returned home from the North African country.
Aaron Yoon arrived at Toronto's Pearson Airport on Friday aboard an Air Canada flight from Paris. He was escorted off the plane by RCMP officers, likely for questioning, said CBC's Adrienne Arsenault.
"There is so much that the police really want to know from Aaron Yoon," she said. "From their perspective, it seems vital to understand what, if anything, he knows about how his friends were radicalized, how that happened, and who did that. And if so, are those people still in Canada, are they still a threat? Police have to urgently figure that out."
Yoon was detained for a brief time, then released, she added.
It will be difficult for Canadian authorities to arrest him, Arsenault said, unless they have "extremely compelling" evidence that he poses a threat to Canada. Yoon’s claim that he was tortured while in detention in Mauritania may invalidate evidence against him collected by investigators in that country, she said.
Yoon was arrested in the North African country in December of 2011, and sentenced to 18 months in jail. He was released from prison there on Tuesday.
The 24-year-old Canadian was convicted of having ties to an al-Qaeda-affiliated group that operates in the North African region, and of posing a danger to Mauritanian national security.
The London, Ont., man had travelled to the area with two Canadian high school friends, Ali Medlej and Xris Katsiroubas. They were later killed while taking part in an attack on a natural gas plant in Algeria last year.
Twenty-seven other attackers and 37 hostages also died in the attack.
Court papers unsealed in New York last week said an Islamic militant named Mokhtar Belmokhtar appeared in an online video the day after the siege ended, claiming responsibility for the attack on behalf of al-Qaeda.
Belmokhtar left al-Qaeda in the Islamic Maghreb, the North African offshoot of the terrorist group, then formed his own spinoff.
Yoon has denied any link to terrorism, saying he went to Mauritania to learn Arabic and study the Qur'an. He has said he doesn't know how Medlej or Katsiroubas became linked with militants, and that he was tortured while in prison.
An official with Canada's Department of Foreign Affairs confirmed that a Canadian had been released from prison in Mauritania, but said the department would not be commenting further on the matter.
Yoon was escorted out of the country by Mauritanian intelligence officials, CBC's Adrienne Arsenault reported. He likely went to Morocco before starting the rest of his journey home by plane, she said.
With files from The Associated Press