Although military officials deny his allegations, Ahmadshah Malgarai is insisting that Canadian soldiers murdered an Afghan teenager.

"It was a murder and I'm standing my ground," he said in an interview with CTV News on Monday.

Malgarai, who worked as a translator and interpreter for the Canadian Forces in Kandahar, was responding to a letter Gen. Walt Natynczyk released late Friday night, outlining a June 18-19, 2007 incident.

Natynczyk wrote that soldiers were conducting an operation on a bomb-making compound when an armed Afghan was identified and killed.

"A shooter who was providing support to the operation identified the individual and assessed that he was a threat, and shot the individual," he wrote. "The acts of the shooter were an appropriate application of the rules of engagement and saved the lives of a number of Canadian Forces members that night."

Malgarai, who first made his allegations on April 14 before a parliamentary committee, insists he heard that Canadian soldiers shot a civilian teenager in the back of the head, and then tried to hide his death. And he alleged that Afghans who were arrested by Canadian troops on the night of the operation were innocent civilians taken into custody as part of a cover-up.

Defence Minister Peter MacKay has dismissed Malgarai's claims as "drive-by smears and unsubstantiated allegations."

Malgarai did not witness the shooting -- instead, he has acknowledged that he heard about the death from other people. On Monday, he claimed he saw secret files and can produce witnesses from Afghanistan to back up his allegations.

The Canadian Forces national investigation service is conducting an assessment regarding the matter, Natynczyk said. He also urged anyone with information about the raid to give a sworn statement.

Malgarai, who is now a Canadian citizen and lives in Canada, says his family faced Taliban death threats after the military leaked his identity, but he's not looking for revenge.

His lawyer, University of Ottawa law professor Amir Attaran, says a public inquiry is the only way to find out who is telling the truth.

"If the Canadian Forces want to get to the bottom of this, and I trust that they do, then they won't rely on shouting down those who raise questions," Attaran said on CTV's Power Play. "What they will do, and what they must do, is provide the evidence they possess to Parliament."

Retired maj.-gen. Lewis MacKenzie said that holding a public inquiry into the matter would be "ridiculous" for national-security reasons. And he said allegations of a cover-up were not credible.

"There is a significant amount of time spent investigating, documenting what happens in every one of these operations, and this one was more than a year in preparation."

With a report from CTV's Roger Smith