A poll suggests 51 per cent of Canadians believe last week's testimony of diplomat Richard Colvin, who alleges that all prisoners handed over by Canadian soldiers to Afghan authorities were likely abused. (Chris Wattie/Reuters)

Canadian diplomat Richard Colvin, who last week gave explosive testimony about the possible torture of detainees captured by the Canadian Forces in Afghanistan, sent reports about the issue to the office of the minister of foreign affairs.

Meanwhile, Liberal MP Bob Rae said Colvin has advised the House of Commons committee investigating the allegations that the government is blocking him from handing over documents related to the issue.

Colvin alleged before a Commons committee last week that all prisoners handed over by Canadian soldiers to Afghan authorities were likely subsequently abused and that government officials were well aware of the problem.

Colvin said he began sending warnings about the mistreatment in May 2006 while serving as a senior diplomat in Afghanistan, but in his testimony before the Commons special committee on the Canadian mission in Afghanistan, he could not say whether he had copied his reports to the minister's office.

But Colvin has revised his statements before the committee in a letter and now confirms some of the reports went to the minister's office at Foreign Affairs.

"At the time, Mr. Colvin advised that he was unable to answer the question precisely, and suggested that he did not typically copy ministers on his reports from the field," Colvin's lawyer, Lori Bokenfohr, wrote in a letter to the chair of the committee. "However, Mr. Colvin has since gone back to verify the accuracy of his response to the committee," the letter said.

"He can now confirm that contrary to his initial answer, he did in fact copy the office of the Minister of Foreign Affairs on some of his reports from Afghanistan that relate to detainees."

During question period Wednesday, Rae said Colvin informed the committee that he has been told by Justice Department lawyers not to disclose those documents.

"It's very clear that the only party in this House that is restricting evidence coming before the committee and coming before the House of Commons is the Conservative Party of Canada and the government of Canada," Rae said.

Defence Minister Peter MacKay said the government has been co-operating and turning over documents relevant to the investigations.

MacKay denies seeing reports

The news came as three generals were scheduled to appear before the committee Wednesday, the same day a survey indicated Canadians are more than twice as likely to believe Colvin than to view his testimony with skepticism.

Laurie Hawn, the parliamentary secretary to MacKay, told CBC News he hasn't seen the letter clarifying the testimony and said the timing of Colvin's emails would play a role in whether MacKay, in his former role as foreign affairs minister, would have seen them.

MacKay served as foreign affairs minister during much of Colvin's time in Afghanistan. Maxime Bernier took over the position in August 2007.

Canada began turning over captured detainees to Afghan security services in late 2005 but briefly halted the transfers after receiving a report in October 2007 that there was evidence the prisoners were then being tortured.

MacKay says he never saw Colvin's reports and never received a credible report on torture apart from the one in October 2007.

Canadians tend to believe Colvin: poll

A Canadian Press-Harris/Decima survey released Wednesday suggests twice as many Canadians believe Colvin's testimony than believe, as the government states, that he lacks credibility.

The survey found 51 per cent of respondents believed Colvin's statement that prisoners handed over by Canadian soldiers to Afghan authorities were likely abused and that the government knew of the problem.

Twenty-five per cent said they believed the Harper government's assertion that Colvin's claims are flimsy.

Harris/Decima chairman Allan Gregg said the results suggest the government's strategy of attacking Colvin's credibility has backfired.

"You don't need to be a rocket scientist or a pollster to know that there's something unseemly about taking an allegation that appears to be heartfelt and twisting it around and throwing it back in someone else's face," Gregg said in an interview.

Hawn said he was unsurprised by the poll results, since it followed Colvin's testimony.

"Let's not go rushing off with our hair on fire based on the testimony of one individual," Hawn said.

"Canadians have only heard one side. Of course they are going to believe that side. Let all the stories come out and then let Canadians decide, and then that will be the more meaningful poll."

The poll involved telephone interviews with 2,036 Canadians from last Wednesday to Sunday and has a margin of error of plus or minus 2.2 percentage points, 19 times out of 20.

Government pins hopes on generals

The government's efforts to get other versions of events heard begins Wednesday when Rick Hillier, former chief of defence staff, is scheduled to testify at the Commons special committee.

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

David Mulroney, a former senior adviser to Harper on Afghanistan and now Canada's ambassador to China, wants to appear before the committee on Thursday to tell his side of the story, after Colvin named him last week as one of the officials he reportedly spoke to about the torture allegations.

But opposition parties are threatening to delay Mulroney's appearance before the committee until they have had a chance to pore over the relevant documents.

Liberal defence critic Ujjal Dosanjh said he does want to hear from Mulroney, but said the opposition parties need information in order to ask Mulroney the right questions. He said the Harper government's push to schedule an impromptu hearing day on Thursday to hear Mulroney is an attempt to hijack the committee.

"The government wants to change the agenda of the committee and impose witnesses on the committee this government wants," Dosanjh said.

Hawn told the CBC that some of the government documents detailing correspondence would be released to the committee.

With files from The Canadian Press