"Yesterday afternoon coalition leaders were notified of an allegation of detainee abuse," US military spokesman Lieutenant Colonel Tucker Mansager said.

"On notification, coalition forces immediately launched an investigation into this matter. The investigation continues," he told Kabul press conference.

The inquiry will report to Combined Force Command Afghanistan by officers from the army criminal investigation division, he added.

The investigation follows a report in the New York Times about an Afghan police officer who was held at the US military headquarters at Bagram air base, north of Kabul, and a base in southeastern city Gardez in August 2003.

He told the paper he was stripped naked, kicked and subjected to sexual taunts. The American embassy in Kabul also confirmed Wednesday that an inquiry into an allegation of prisoner abuse was underway.

"The US military has launched an investigation," the embassy said in a statement. US ambassador Zalmay Khalilzad said he was confident "appropriate action" would be taken if the allegations were found to be true.

"To the best of our knowledge this is the first time that anyone in the military chain of command or the United States embassy has heard of this alleged mistreatment," he said in the statement.

The embassy was unaware of the existence of any photos of the alleged incident, he added.