University of Ottawa law professor Amir Attaran says Canadian officials intentionally handed over Afghan detainees to be tortured in order to gather intelligence. (CBC)

Federal government documents on Afghan detainees suggest that Canadian officials intended some prisoners to be tortured in order to gather intelligence, according to a legal expert.

If the allegation is true, such actions would constitute a war crime, said University of Ottawa law professor Amir Attaran, who has been digging deep into the issue and told CBC News he has seen uncensored versions of government documents released last year.

"If these documents were released [in full], what they will show is that Canada partnered deliberately with the torturers in Afghanistan for the interrogation of detainees," he said.

"There would be a question of rendition and a question of war crimes on the part of certain Canadian officials. That's what's in these documents, and that's why the government is covering up as hard as it can."

Detainee abuse became the subject of national debate last year after heavily redacted versions of the documents were made public after Attaran filed an access to information request. They revealed the Canadian military was not monitoring detainees who had been transferred from Canadian to Afghan custody. It was later alleged that some of those detainees were being mistreated.

Diplomat Richard Colvin says he warned top Canadian officials as early as 2006 that Afghan detainees handed over to Afghans were subsequently being tortured. (Sean Kilpatrick/Canadian Press)

Until now, the controversy has centred on whether the government turned a blind eye to abuse of Afghan detainees.

However, Attaran said the full versions of the documents show that Canada went even further in intentionally handing over prisoners to torturers.

"And it wasn't accidental; it was done for a reason," he said. "It was done so that they could be interrogated using harsher methods."

The government maintains that nothing improper happened.

"The Canadian Forces have conducted themselves with the highest performance of all countries," Prime Minister Stephen Harper told the House of Commons Thursday.

But many facets of the issue remain top secret, such as the role of Canada's elite Joint Task Force 2, or JTF2. There have been hints that JTF2 might be handling so-called high-value prisoners.

"High-value targets would be detained under a completely different mechanism that involved special forces and targeted, intelligence-driven operations," Richard Colvin, a former senior diplomat with Canada's mission in Afghanistan, told a parliamentary committee last November.

Colvin claimed that all detainees transferred by Canadians to Afghan prisons were likely tortured by Afghan officials. He also said that his concerns were ignored by top government officials and that the government might have tried to cover up the issue.

Opposition parties have been trying to get the Conservative government to release the uncensored versions of the documents pertaining to the handling of Afghan detainees.

Retired Supreme Court justice Frank Iacobucci has been asked to review whether documents pertaining to the transfer of Afghan detainees can be released to Parliament. (Adrian Wyld/Canadian Press)

The Conservatives insist that releasing uncensored files on the issue would damage national security. On Friday, Justice Minister Rob Nicholson asked former Supreme Court of Canada Justice Frank Iacobucci to review whether there would be "injurious" effects if some Afghan detainee documents were made public.

Nicholson did not give full details on Iacobucci's assignment or a timetable for when the review might be completed.

However, opposition parties said Parliament is entitled to those documents regardless of what Iacobucci decides.

"Parliament is supreme," said Ontario NDP MP Paul Dewar. "What this is, is a skate around Parliament."

Liberal MP Ujjal Dosanjh said the government still has many questions to answer on the subject of detainees.

"Who knew what and when, and who allowed the continuing saga of Afghan detainees being sent to a potential risk of torture?" Dosanjh said.

It's not clear whether the government will make Iacobucci's advice public. Moreover, he is not a sitting judge and can't legally rule or force the government to do anything.