An authority on the Tamil Tigers says Canadian Ravi Shankar Kanagaraja masterminded the shipment of migrants to Canada's West Coast. (CBC)

The Tamil Tigers organization hopes to use Canada as a strategic base to continue the fight against the government of Sri Lanka, according to an authority on the alleged terrorist group.

"I cannot think of any other country that is more important for the Tamil Tigers as Canada, to regroup and continue their campaign against Sri Lanka," said Prof. Rohan Gunaratna, head of the International Centre for Political Violence and Terrorism Research, a Singapore-based think-tank.

Gunaratna is advising the Canadian government as it investigates the 75 Tamil migrants currently in immigration custody in Vancouver. The men were found aboard a ship seized off the coast of British Columbia on Oct. 17.

Lawyers for the men have said they are not Tamil Tigers, but Gunaratna disagreed.

"There are many members of the Tamil Tigers on board that vessel," Gunaratna said in an interview from Singapore. The Tigers — banned in Canada as a terrorist organization — were defeated in May 2009 after a 23-year insurgency.

Alleged mastermind named

Gunaratna also alleged that a Canadian — Ravi Shankar Kanagaraja — was the mastermind behind the ship's arrival.

"He arranged for this ship to come to Canada, and right now the Canadian authorities are hunting for him," Gunaratna said.

One of the lawyers for the men has accused Gunaratna of bias because of his past association with Sri Lanka's government.

Men on the ship seized off the coast of British Columbia wave to a helicopter Oct. 17. Government investigators are trying to determine if some of the men pose a risk to security. (RCMP)

"If they are going to make allegations that people are connected to the Tamil Tigers, they'd better have evidence and, from my point of view, Mr. Gunaratna is not credible," said Lorne Waldeman.

In Ottawa, Immigration Minister Jason Kenney suggested Tuesday he was heeding the advice of the government's expert for now.

"It's our view [the migrants] constitute a flight risk and we are not entirely satisfied about their backgrounds," Kenney said.

An immigration hearing Monday for one of the migrants was told that residue of two chemicals used in explosives was found on clothing owned by two of the men aboard the vessel.

Monday's hearing was also told that the identity of the ship was hidden on its voyage to Canada because it was known to have been used to ship arms for the Tamil Tigers.

Lawyers representing the men are seeking to have them accepted as refugees in Canada, and say the men's lives would be in danger if they were forced to return to Sri Lanka.