CBC News says it has identified the two Canadians involved in January's deadly terrorist attack at an isolated Algerian gas plant.

Citing unidentified sources, the news outlet says Ali Medlej and Xristos Katsiroubas, high school friends who were both from London, Ont., were the Canadians whose bodies were found amidst the carnage.

CBC says the Canadian Security Intelligence Service was asking questions about both men at one point after a family member contacted authorities in 2007 with concerns that the pair were associating with the wrong crowd.

But the report says CSIS did not have the two men, who were thought to be in their mid-20s, under surveillance when they left Canada for Algeria sometime last year.

Photo: Contributed - CBC

The report also says it has learned that two other individuals from the London area travelled to Algeria with Medlej and Katsiroubas, but it isn't known if they were involved in the gas plant attack or if they're even alive.

Sgt. Greg Cox, a spokesman for the RCMP, says the force's investigation into Canadian involvement in the attack continues and added that no further information would be provided at present.

At least 38 hostages and 29 militants were killed in the four-day siege of the natural gas plant that ended when the Algerian military stormed the energy complex.

In the aftermath of the attack, Algeria's prime minister had said two Canadians were among the band of militants who took hundreds of workers hostage, claims Canada couldn't initially confirm.

Hostages who escaped recalled hearing at least one of the militants speaking English with a North American accent.

Members of the RCMP were sent to Algiers to investigate.

In March, the Mounties first said a Canadian was among those killed in the attack, but wouldn't say if the remains were discovered among the al-Qaida linked terrorists or the hostages.

Later in the month, the RCMP said the second Canadian was identified from among the bodies of the men accused of being terrorists.