Afghanistan's security service blocked Canadian efforts to get a human rights group's access to Afghan jails for three months in 2007, according to uncensored documents obtained by CBC News.

A version of the same document released by the federal government was heavily blacked out, but the uncensored version was leaked on Wednesday.

The Afghan human rights agency was appointed by Canada to be its eyes and ears in Afghan prisons at the time. The rights group was supposed to help ensure the safety of detainees who had been transferred from Canadian troops to the Afghans. The Afghan security service, the NDS, took those detainees from the Canadians.

The uncensored version of the document states there were "... five failed attempts to access Kandahar NDS facilities in 2007."

The document says the NDS response on detainee access was often, "You have your law, we have ours." It says Afghan human rights experts "discussed the access problem with [Afghan] President [Hamid] Karzai ... however, this did not help."

Cory Anderson, a former senior political adviser to Canada's provincial reconstruction team in Kandahar, echoed other concerns about the NDS during his testimony before a House of Commons committee on Afghanistan Wednesday

Anderson said there is "...endemic and systemic duplicity within the NDS, especially at the provincial level, that exists to this very day, and renders it virtually impossible to have an open and transparent relationship with their officials on the ground in Kandahar on this issue."

The diplomat noted that Canada is still handing over detainees to NDS, and he agreed the detainee issue was a potential "mission-killer" for Canada's efforts in Afghanistan.

'Doesn't change the partnership'

Anderson said Canada's original prisoner transfer agreement wasn't good, and the current prisoner transfer agreement isn't good enough, either.

"It doesn't change the partnership that we have with the people on the ground in Kandahar, who we are bound to work with, in the NDS," he said.

Anderson claimed the problem with the NDS is they are too secretive, and that they have no interest in working with Canadian officials to improve the lot of detainees. He said Canada should cut its detainee ties with the NDS.

Asked by committee member Liberal MP Ujjal Dosanjh if he considered the NDS to be a viable partner while he was in Afghanistan, Anderson replied: "No, they were not."

The uncensored documents and the diplomat's testimony came as the government continued its fight to keep MPs from getting full access to Afghanistan documents.

The opposition won a vote three months ago demanding uncensored versions of all documents.

However, on Wednesday, Justice Minister Rob Nicholson again said no.

"The practice of this House, and in other jurisdictions, has always been to acknowledge that some information ought not to be disclosed for considerations of public policy or national security," Nicholson said in the House of Commons.

There could be a constitutional showdown after MPs return from their Easter break. The Speaker of the House of Commons is set to rule on whether Parliament is entitled to see the uncensored documents.