A Canadian militant involved in the bloody takeover of an Algerian gas plant a year ago attempted a suicide bombing in the final stages of the attack, using an improvised bomb he built himself.

In an interview with a former hostage, CBC’s The National obtained new details about the nature of Xristos Katsiroubas’s role in the attack, including the first known grainy images of him captured surreptitiously on cellphones during the crisis.

The interview and images will air tonight on The National.

As CBC News previously reported, the London, Ont. native acted as a negotiator and translator for the militants, who called themselves The Signatories in Blood Brigade, a group with links to al-Qaeda.

Stephen McFaul

Stephen McFaul, a Belfast-born electrical engineer who was taken hostage in the Algeria gas plant attack, escaped many brushes with death during the attack, including an attempted suicide bombing by Canadian militant Xristos Katsiroubas. (Pascal LeBlond/CBC)

Katsiroubas also assisted in building bombs and appeared to handle explosives and weaponry — including a heavy machine gun — with knowledge and ease.

It has now emerged that he also helped string hostages together with explosive cord wrapped around their necks, and threatened one at gunpoint against fleeing, said Stephen McFaul, a Belfast-born electrical engineer who spent hours as one of the hostages observing and occasionally speaking to Katsiroubas.

The militant also deftly used a machine gun to try to bring down an Algerian army helicopter, says McFaul.

"The Canadian terrorist in particular, he had actually seated himself … and put the machine gun between his two feet like a tripod, and was trying to shoot up at the helicopter once it was coming in," McFaul said.

"There was gunfire coming from everywhere."

In a chilling, two-hour interview, McFaul told an incredible story of surviving several brushes with death during the crisis.

These ranged from the militants shooting at him in the first minutes of the attack, to repeated barrages of Algerian army artillery, to the fiery crash of an escape vehicle he was forced to ride in with Katsiroubas, who was carrying a suicide bomb in his lap, a detonator in his hand.

Defying death

The attack began on Jan. 16, 2013, when more than 30 al-Qaeda-linked militants barged into the gas plant near In Amenas, Algeria, taking foreign workers hostage. McFaul was among those gathered in a central courtyard and strung together with detonating cord.

That is where he met Katsiroubas, and would spend the next day observing and occasionally speaking with him.

Algerian workers were left to roam relatively freely, and many of them used cellphones to surreptitiously document the swift capture of their foreign colleagues near the living quarters.

McFaul has since studied much of the available footage, but CBC showed him one particular photo he had not seen.

Nahlah Ayed listens to harrowing hostage ordeal

The CBC's Nahlah Ayed listens as Irish engineer Stephen McFaul describes his harrowing ordeal of being held hostage in an Algerian gas plant last year. (CBC News)

"This is the group that I was in. This is actually me seated there," he said, pointing at a group of men huddled together against a wall.

He then points out a bent over figure, whose face is obscured, identifying him as Katsiroubas.

"Yeah, it is the same boots he was wearing, yeah. That's actually him," he said, visibly upset.

Based on McFaul’s discovery, The National was able to identify Katsiroubas in grainy cellphone video, standing upright, and walking away from the same scene.

Final ride

McFaul says Katsiroubas acted as spokesman for the militant in charge, Mohamed Lamine Bin Shnib. Katsiroubas consulted with him regularly, and referred to him as "al Taher," or the pure one.

At one point, Katsiroubas marched McFaul at gunpoint to a warehouse at the plant to retrieve material — including screws and fire extinguishers — which the militants later used to build a makeshift bomb. While walking behind him, McFaul said Katsiroubas warned "that if I tried to run they would shoot."

McFaul described Katsiroubas as aggressive, and overheard him on the phone threatening to blow up the plant and kill hostages if their demands were not met.

Xris Katsiroubas in Algeria attack

This image, taken from cellphone footage, shows Canadian Xristos Katsiroubas taking part in the hostage-taking at a gas plant in Algeria last year. Thirty-eight people were killed in the attack. (AFP/Getty Images )

McFaul’s memories though are dominated by that final ride with the militant on the second day of the hostage taking, a ride which, to McFaul, felt like a suicide mission.

The militants had forced the hostages, 34 in all, into SUVs and into what McFaul believed was a journey he would not survive. He was sitting behind Katsiroubas and his bomb.

"They had started to whip themselves into a frenzy they were chanting ‘Allah Akbar’ in the car, they were firing gunshots out the windows of the car.

hi-three-youths-london-852

Aaron Yoon, Ali Medlej, and Xris Katsiroubas, all from London, Ont., travelled to North Africa together before an attack on an Algerian gas plant. Medlej and Katsiroubas participated in the attack. Yoon was arrested in Mauritania before the attack. He's since been released. (CBC News )

"We did not know what way this was going. So me and the colleague who was sitting beside me just said a brief few words and, yeah, that's it. ‘Good luck.’"

Their vehicle was pursued by an army helicopter that was shooting directly at them, said McFaul. That was terrifying enough, he said, but was nothing compared to the memory of hearing Katsiroubas trying to set off his bomb.

"Our vehicle overturned and came to rest. At this point, the Canadian terrorist then tried to detonate the explosive that he was carrying," said McFaul.

"You heard the fused wire I guess of the ‘shhhh’ hissing noise from whatever he was trying to detonate, and I think it was his detonating wire."

McFaul escaped the vehicle, which had caught on fire. Of the 34 hostages in that convoy, only five survived.

As he got away, McFaul looked back and saw Katsiroubas running in the opposite direction, towards the central processing facility. That is where intelligence officials believe Katsiroubas eventually died, possibly in a group suicide explosion with other militants and the remaining foreign hostages.

'If it has happened once there is potential to happen again. And next time it may not be on foreign soil, it may be in Canada,'- Stephen McFaul, who was held hostage in the Algerian gas plant attack

McFaul says he has questions for Canadian authorities on why Katsiroubas and at least two other Canadian youth were allowed to travel to the region despite being on their radar as possible radicals.

McFaul says Canadians should be concerned.

"If it has happened once there is potential to happen again. And next time it may not be on foreign soil, it may be in Canada," he said.

He added he is also bewildered that one Canadian, Aaron Yoon, who had served 18 months in a Mauritanian jail for links to terrorism, is now a free man in Canada. Yoon denies any wrongdoing and says he was tortured into confessing.

As for Katsiroubas, McFaul said: “He is just an idiot. A fool."

Watch more of Stephen McFaul’s interview on CBC: The National tonight.