Canadian soldiers were given permission to interrogate detainees captured by Afghan security forces, and at least one soldier followed through, according to documents released Thursday by the federal government.

In at least one case, a soldier assigned to question an Afghan prisoner later expressed concern Afghan forces had abused the detainee before the questioning took place, the documents say.

The revelation is contained in more than 2,500 pages of military detainee documents tabled Thursday by the Conservative government. The documents also show it took almost two years for military police to get around to investigating the soldier's allegation.

A Canadian soldier who in 2007 helped Afghan security forces interrogate a prisoner later told his boss he worried the detainee had been abused. The soldier recounted his story to Canadian Capt. Simon Parker.

At the time, Parker was second in command of an infantry company in Afghanistan. He was also responsible for a small group of soldiers employed as "tactical questioners."

In a February 2007 email, Parker wrote that the Canadian Forces needed to better prepare Canadian questioners for the rigours of working with Afghans because they "don't follow our policies on detainee handling if you know what I mean."

In the email, Parker relayed parts of a discussion he had with his soldiers after one of them told Parker he had been asked by Afghan security forces to help interrogate a detainee.

The soldier said he received permission from his Canadian chain of command — even though Canadian troops had nothing to do with the capture. He noted the detainee appeared injured and had been engaged in labour, working to stack a pile of bricks.

The soldier told Parker questioning the detainee made him feel uncomfortable, and Parker relayed the soldier's story in an email to colleagues. The email wound its way through the military's intelligence and special forces branches before landing in the hands of military police in April 2007.

The email is contained in detainee documents released by the government yesterday. According to those documents, the military police were too busy to investigate the allegations in Parker's email until nearly two years later.

They ended the investigation after they learned the detainee had not been captured by Canadians but by Afghans.