A Toronto man has been flagged by Interpol as a potential ISIS suicide bomber, although it’s not clear whether he is even still alive.

Tabirul Hasib, 25, was among four young men with Bangladeshi backgrounds who left Toronto five years ago to join ISIS in the Middle East.

They were recruited by Andre Poulin, who grew up playing hockey in Timmins, Ont., and later appeared in ISIS propaganda as Abu Muslim Al Kanadi. Poulin died in Syria in 2013.

Hasib returned to Canada but later left again to fight in Syria.

If Interpol’s information is correct, he has been transformed from a front-line fighter to a potential suicide bomber going by the name Abu Baku al-Bangladeshi.

Radicalization expert Amarnath Amarasingam, a fellow at the George Washington University's Program on Extremism who spotted the Toronto man’s name on the Interpol list, says it’s not clear whether Hasib is alive.

“It’s often very difficult to know when they’ve been killed,” he told CTV News Channel.

Although Amarasingam says Canada is not immune to attacks by ISIS terrorists, a much bigger cause for concern is that someone like Hasib will launch an attack in Europe.

Amarasingam said the fact that many of the 173 people on the Interpol list are Iraqis is especially concerning because are less likely to be “on the enforcement radar” in Europe.

“We might not actually know who they are because they don’t have a criminal record in Europe, documents in Europe and so on,” he said.

The Canadian government, meanwhile, will not say whether it believes Hasib is alive.

Scott Bardsley, a spokesperson for Public Safety Minister Ralph Goodale, told CTV News in a written statement Sunday that the government does not comment on national security operations.

“We can say that the Government of Canada monitors all potential threats and has robust measures in place to address them,” Bardsley said.

The government last year estimated that as many as 180 Canadians have gone abroad to fight with ISIS. Some have been killed, some have returned and others remain a risk.

With a report from CTV’s Glen McGregor