Defence Minister Peter MacKay says the most recent pause in detainee transfers occurred because Canadian government officials could no longer have "unfettered unannounced visits" to the prisons. (Sean Kilpatrick/Canadian Press)

Canada halted the transfer of detainees to Afghan prisons three times in 2009 over concerns of treatment of prisoners and access to facilities, officials in Ottawa said Monday.

A statement on the Canadian government's Afghanistan mission website said the transfers were temporarily halted twice in 2009 because of allegations about treatment.

The more recent pause in transfers was related to access to facilities, the statement said.

During question period in the House of Commons, Defence Minister Peter MacKay expanded on the most recent pause, saying it occurred because Canadian government officials could no longer have "unfettered unannounced visits" to the prisons.

"When Afghans are not living up to their expectations, we pause transfers. When they started to allow that access again, the transfers then began again," MacKay said.

All pauses were for brief periods of time.

Last week Richard Colvin, a former Canadian diplomat in Afghanistan who says he delivered repeated warnings that prisoners handed over to Afghan authorities were being tortured, told a House of Commons committee looking into the Afghan mission that all of the prisoners Canada handed over in 2006-07 were likely tortured.

He also testified that his concerns were ignored by top government officials and the government may have tried to cover up the issue.

The Tories have attacked the credibility of Colvin’s testimony, but Foreign Affairs Minister Lawrence Cannon said Monday that Colvin had the right to make the allegations he did.

"Our government put in very tough regulations enabling the employees of the government through our whistleblower legislation to be able to come forward and make their comments known," he said.

"Mr. Colvin has exercised his prerogative in that regard and, in this case, his allegations are not proven. The parliamentary committee is working, so we'll wait until the parliamentary committee has completed its findings."

Mulroney denies hushing concerns

While testifying, Colvin singled out David Mulroney — then a deputy minister of the Afghanistan Task Force — as one of the officials who didn't want to hear allegations of abuse.

Mulroney, the current ambassador to China, has flown back to Canada and has asked to testify in his defence before the parliamentary committee on Thursday. He wrote a letter to the committee chairman, Conservative MP Rick Casson, denying allegations that he was instructed by superiors to stop filing written reports on the treatment of detainees.

"I can also assure the committee that I encouraged officials to report freely and honestly, while expecting them to meet the highest standards of accuracy, objectivity and professionalism," Mulroney wrote.

More testimony is expected Wednesday, including appearances at the commitee by former chief of defence staff Rick Hillier, who oversaw Canada's mission in Afghanistan.

Also scheduled to appear are Maj.-Gen. David Fraser, who led troops on the ground in Kandahar, and Lt.-Gen. Michel Gauthier, who was responsible for overseas deployments in 2006.

Meanwhile, New Democrat MPs submitted a motion to the committee demanding access to all government documents relevant to the torture of Afghan detainees, including Colvin's reports.

"The government is hiding the truth, and making a mockery of this committee, by refusing to release the documents it has in its possession," said Paul Dewar, the NDP foreign affairs critic.

"Conservatives have quashed access to information on this file since Day 1. The committee has clear powers to shed light on these documents and we fully intend to exercise our right to know the facts."

Liberals have also demanded the documents be released.

With files from The Canadian Press