Australia went to war in Afghanistan without a clear policy on how to deal with enemy detainees, according to secret papers that reveal one of Canada's military allies was just as fraught over what to do with captured militants.

When a policy was adopted, the then chief of the armed forces expressed reservations about the legality of the agreed approach.

The documents also show that the public was never told about the death of an Iranian man captured by Australian troops in 2003.

The papers, obtained under freedom of information laws by the Sydney-based non-profit Public Interest Advocacy Centre, reveal utter confusion at the highest levels of the Australian government and the Department of Defence over how to deal with enemy detainees.

On Feb. 25, 2002, as Australian troops fought in Afghanistan, armed forces chief Admiral Chris Barrie wrote to the country's then defence minister complaining his commanders were being put at risk.

"There is currently no clear government policy on the handling of personnel who may be captured by the ADF," the Australian Defence Force, Barrie wrote. "Defence and in particular ADF commanders are currently accepting the risk flowing from the lack of government policy."

Barrie proposed a set of interim arrangements, such as asking for U.S. help to move captives from where the Australians were in Kandahar to a U.S. detention facility, where an ADF team could supervise any prisoners captured by Australians.

Then defence minister Robert Hill gave permission for Barrie to negotiate with the United States and added a series of handwritten comments at the end of Barrie's missive.

"I don't understand why I didn't get this brief before the Afghanistan operation," he wrote. "We clearly should have sorted out this issue with the U.S. as leader of the coalition months ago."

What emerged from the negotiations became Australia's detention policy in Afghanistan and Iraq: that if even a single U.S. soldier was present when Australian forces captured enemy fighters, the U.S. and not Australia would be recognized as the "detaining power".

In a paragraph with words redacted, Barrie expressed reservations about the legality of this approach.

"Such an arrangement may not fully satisfy Australia's legal obligations and in any event will not be viewed as promoting a respect for the rule of law," he concluded.

Iraq death

The documents also reveal an Iranian man who was captured in Iraq by Australian special forces troops in 2003 died while being transferred to Baghdad.

Then ADF chief General Peter Cosgrove told the government of the death of 43-year-old Tanik Mahmud, but the Australian public was never informed.

Mahmud was among 66 enemy personnel that a team of 20 troops intercepted in Iraq's western desert on April 11, 2003. They were caught on a bus carrying almost $1 million, apparently to pay for bounties on the heads of U.S. soldiers.

The special forces helped detain the men — from Iraq, Syria and Iran — for 10 hours before Britain's Royal Air Force transported them to U.S. detention facilities in Baghdad.

When the Chinook helicopters landed in the Iraqi capital, Mahmud was dead.

The Department of Defence and the Australian government were aware of the problem but chose not to tell the public about it.

Australia's experience with detainees comes in the wake of concerns over how Canadian forces handled militants captured in Afghanistan. Canada has been accused of handing over its captives to Afghan authorities with full knowledge they would be tortured.