On Sept. 19, 2014, the so-called Islamic State released a gruesome video in which Syrian prisoners dug their own graves, and were then lined up and executed.
But what struck some observers was the narrator.
He sounded Canadian.
“Yup, it’s another Canadian,” Muhammed Ali, an ISIS member from Mississauga, Ont., told Global News in a recent interview inside the Syrian prison where he is being held by Kurdish fighters.
Ali said the Canadian went by the alias Abu Rudwan, was in his 20s and “might be” from Toronto. He was a full-time member of the ISIS media division and had not yet been killed, he said.
“Abu Rudwan is alive,” Ali said. “Maybe he’s dead now, I don’t know. Last I saw him he was alive.”
The video appears to have two narrators. One is only heard while the other is show on camera and appears to conduct an execution. It’s unclear which one Ali was referring to.
But the statement supports speculation that a Canadian has been narrating ISIS English-language recruitment videos and claims of responsibility for some of its deadliest attacks.
Both the RCMP and FBI have been investigating since the ISIS video Flames of War was released four years ago featuring a spokesman with a masked face and a voice that sounded distinctly North American.
WATCH: (WARNING: Video may be disturbing to some viewers) FBI video of narrator ‘presiding over’ ISIS execution
In the video, he aimed a handgun at a kneeling prisoner and appeared to shoot him in the back of the head.
The FBI posted a segment of the video on its website in October 2014 in the hope someone might recognize him. It said the “subject in the video has what is believed to be a North American accent.”
The other narrator heard in Flames of War resurfaced in November 2015, in the ISIS claim of responsibility for the terrorist attacks in Paris that killed 130, most of them at an Eagles of Death Metal concert at the Bataclan theatre.
Then in June 2016, he narrated the English-language ISIS audio statement on the terrorist attack at the Pulse nightclub in Orlando that left 50 dead.
WATCH: Extended interview with Canadian ISIS fighter Muhammed Ali
He is also believed to have narrated an ISIS video tribute to André Poulin, a Muslim convert from Ontario who died in Syria in 2013.
“People actually don’t realize he’s Canadian,” Ali told Global News. “A Canadian would know he’s Canadian. Anyone else would be like, where is he from? He’s Australian.”
Earlier this year, another Canadian told the New York Times podcast Caliphate he had executed captives while serving in ISIS. He has since returned to university studies in the Toronto area and has not been charged.
WATCH: Public Safety Minister Ralph Goodale says there are consequences for Canadians who associate with “vile” terrorist groups
With ISIS on the retreat in Syria and Iraq, the fate of Canadians who joined the group has become the subject of heated debate over what to do with them.
Few have been charged but Public Safety Minister Ralph Goodale said Tuesday that Canada and its allies were collaborating to “assemble evidence from the battlefield that will be usable in courts of law.”
No Canadian investigators have yet spoken with Ali, who was captured by the YPG armed group in northern Syria four months ago, but he said he had been interrogated by American, British and Kurdish officials.
“I’d be shocked if the Americans, knowing he’s a Canadian citizen, would not have told us immediately,” he said.
Gurski said that having a narrator fluent in English like Abu Rudwan added credibility to ISIS propaganda, and showed its ability to recruit globally.
“From a recruitment perspective, it actually speaks to the people here saying, ‘Hey, if that wanker from Mississauga or Hamilton or Calgary can do it, well then so can I,’” said Gurski, who now heads Borealis Threat and Risk Consulting.