A day after a report revealed Canadian officials knew of Omar Khadr's harsh treatment by the U.S. military, Prime Minister Stephen Harper on Thursday repeated vows to leave the case in U.S. hands.

Harper, speaking to reporters in Tokyo following the G8 summit in northern Japan, also distanced his government from the latest revelations.

A Canadian official visiting Khadr in 2004 in Guantanamo Bay, Cuba, was told the U.S. military was depriving the then 17-year-old of sleep for weeks to make him "more amenable and willing to talk," according to a newly released internal report from the Foreign Affairs Department.

"The previous [Liberal] government took a whole range... all of the information into account when they made the decision on how to proceed with the Khadr case several years ago," he said.

"Canada has sought assurances that Mr. Khadr, under our government, will be treated humanely. We are monitoring those legal processes very carefully."

Canada "frankly has no real alternative" to the U.S. legal process, he went on to say.

'Absolutely shameful'

Back in Canada, the Liberal Party's foreign affairs critic, Bob Rae, took issue with Harper's assertions and described the military tribunal that will try Khadr as akin to "martial law."

"I think we should be doing everything we can to get Mr. Khadr home," Rae told CBC News, "He went into a training camp when he was 13; he went into Afghanistan when he was 15. I think he should be brought home, and he should face justice here."

Rae said he couldn't answer for the actions taken by earlier Liberal governments at a time when he wasn't a member of the party.

Speaking in Washington, Khadr's U.S. lawyer, Lt.-Cmdr. William Kuebler, questioned why Canada is the last Western country with a citizen at the U.S. naval base.

"It's absolutely shameful … notwithstanding all that we know now about Omar Khadr's treatment in Guantanamo Bay, about his arguably torture and at the very least inhumane and degrading treatment at the hands of U.S. authorities," Kuebler told CBC News Thursday morning.

Kuebler said that whether sleep deprivation falls into the definition of torture is not the issue, but rather that Khadr was a child at the time.

"You're not talking about techniques employed on an adult. You're talking about techniques employed on a minor," he said.

Khadr on 'frequent flyer program': report

The report — dated April 20, 2004, and written by R. Scott Heatherington, who was the director of the department's foreign intelligence division — states Foreign Affairs official Jim Gould was told Khadr was placed on a "frequent flyer program" for three weeks before Gould's visit. That meant Khadr was "not permitted more than three hours in any one location.

"At three-hour intervals, he is moved to another cellblock, thus denying him uninterrupted sleep," according to the report. "He will soon be placed in isolation for up to three weeks, and then he will be interviewed again."

The report notes Khadr did not appear much affected by the sleep deprivation and refused to answer questions, all the while "smiling broadly" and appearing to enjoy the two-hour exchange with Gould on March 30, 2004.

"He did not yawn or indicate in any way that he was tired throughout the two-hour interview," likely a result of the "natural resilience of a well-fed and healthy 17-year-old," the report says.

Khadr denied knowing family

The Toronto-born Khadr, now 21, is at the U.S. naval base in Cuba awaiting trial before a military commission on charges he murdered a U.S. army sergeant in Afghanistan in 2002.

The documents released Wednesday to the media by Khadr's lawyers follow the Supreme Court decision in May that Khadr has a constitutional right to see certain videos and documents held by the Foreign Affairs Department, the RCMP and the Canadian Security Intelligence Service.

The items relate to interviews Canadian officials conducted with Khadr during his detention at the U.S. naval base in Cuba in 2003 and 2004.

In Heatherington's report, he also describes an incident with a U.S. Defence Department interrogator in which Khadr was shown a picture of his family, but denied knowing anyone in the photo.

When Khadr was left alone with the picture, he urinated on it, Heatherington writes.

After he was cleaned up and his shackles shortened to prevent him from doing it again, he still managed to lower his pants and urinate on the picture, the report says.

He was cleaned up a second time. After 2½ hours passed, Khadr "laid his head down on the table beside the picture in what was seen as an affectionate manner," likely assuming he was no longer being watched, the report says.

Heatherington says Gould described Khadr as a "screwed up" young man abused by many people in positions of authority for their own purposes, including fellow detainees and even grandparents and parents. His father was an avowed al-Qaeda sympathizer before he was killed in fighting with Pakistani military forces in 2003.

The report describes Khadr as a "Mama’s little boy" who demonstrates very little independent thinking and has likely found pseudo-parents among other detainees, believed to be coaching him on what to say.

With files from the Associated Press