A Canadian military adviser who served in Afghanistan during a bloody October battle against the Taliban has been charged with second-degree murder in the death of an unarmed Afghan man, defense officials said Friday.

Capt. Robert Semrau is accused of shooting the man "with intent to kill" in Helmand province, where Afghan soldiers, their Canadian officers and British troops had been defending the capital of Lashkar Gah from persistent attacks by insurgents, the Department of National Defense said in a statement.

As a member of the Operational Mentor and Liaison Team (OMLT), the Canadian military unit that coaches the fledgling Afghan National Army, Semrau's responsibilities included helping to guide and counsel Afghan troops military tactics and the rules of war.

The Canadian Forces National Investigation Service, the major crimes unit of Canada's military police, charged Semrau on Wednesday, the defense department said — the same day it revealed it was probing a death that took place in Helmand "on or about" Oct. 19.

Semrau is being held by military police before being returned to Canada, where a military judge will decide whether he should remain in custody.

Military officials at Kandahar Airfield refused to elaborate on a news release issued Friday by the Department of National Defense.

At the time of the incident, Semrau was among several Canadian military advisers who were in Helmand for the bloody three-day defense of Lashkar Gah. Also taking part were British forces, who are deployed extensively in Helmand.

Afghan and foreign troops eventually retook the Nad Ali district center, which had been held by insurgents, after a three-day fight. That battle, which also involved air strikes, ended Oct. 18. Afghan and NATO officials claimed at least 100 Taliban died in the fighting.

Afghanistan's ambassador to Canada, Omar Samad, said the allegation should not taint all the work done these past few years by Canadian military advisers.

"One needs to put this in context, which means that the training and mentoring provided by Canadians so far has been exemplary," he said.

"Like in any other situation, there may be some flaws or some mistakes that are made, and this may be one of them."