Guantanamo Bay detainee and Canadian citizen Omar Khadr could serve another 10 years in jail if a reported plea deal is worked out by lawyers and government officials.

Khadr, who is now 24, has been in detention for eight years for allegedly killing a U.S. soldier on the battlefield in Afghanistan.

On Friday afternoon, CTV Ottawa Bureau Chief Robert Fife reported that a plea deal in the case was close to being struck. The deal would see Khadr plead guilty in the case and avoid a complicated and lengthy trial.

"Mr. Khadr would serve five years in an American prison and five years in a Canadian prison," Fife reported. "That would be on top of the eight years he's already served at Guantanamo Bay."

Though the Canadian government has refused to specifically comment on the case, Fife said that a lawyer representing Ottawa has been part of the negotiations. He added that all sides are pushing for a deal because no one wants to see the war crimes case go to trial.

"Mr. Khadr would be the first person since the Second World War to be facing war crimes (charges) as a minor," said Fife, adding that defence lawyers also want to avoid the potential life sentence in the case.

Khadr was 15 and badly wounded on the battlefield at time of his detainment.

Fife noted that the Obama administration is keen to see the case resolved, and Ottawa is also facing mounting political pressure to ensure that the case is finally dealt with.

"The Canadian government has said that there is no such agreement, and they've left the impression that they are not involved in this. But American sources have told me that in fact, (a) Canadian government lawyer is sitting at the table," said Fife.

Earlier in the day, Prime Minister Stephen Harper repeated his party's line, and said that the case must play itself out in the U.S. before Ottawa can intervene.

If Khadr pleads guilty, however, it's unlikely that he would serve out the full sentence, said Fife.

Pointing to a similar case of an Australian detainee, Fife said that once Khadr finished a five-year stint in the U.S., Canadian authorities would likely release him within months of his Canadian return.

With files from The Canadian Press