"This week the coalition reviewed a new allegation of detainee abuse occurring within its area of responsibility," US military spokesman Major Jon Siepmann said. "The Naval Criminal Investigation Service is looking into the allegation."

Two allegations of prisoner abuse emerged in Afghanistan following international outcry over the treatment of detainees in Iraq. The allegations are believed to include assault, living conditions and sleep deprivation.

Siepmann said he was unable to comment on where or when the latest abuse supposedly took place or any other details regarding the allegation.

"Right now it's just an allegation, we don't know that anything in particular occurred," he said. "We cannot release any of the details of the investigation itself."