US and local troops in Afghanistan have been accused of abusing a prisoner by two German journalists embedded with the 82nd Airborne Division.
US and Afghan troops are working together to hunt Taleban fighters
The alleged abuse reportedly witnessed by reporter Wolfgang Bauer and photographer Karsten Schoene was set out in an article in Focus magazine.
Troops allegedly tied a man to a vehicle and said they would drag him behind it if he did not speak.
US military officials say they have begun investigating the claims.
According to the article, a combined US-Afghan patrol led by an Afghan army platoon leader, was hunting for Taleban fighters in Ghazni province, Afghanistan, when they seized a man.
'Engine switched on'
Focus reported that in order to make the man talk, the platoon leader tied a rope around one of the man's feet, which he attached to the back of the patrol's vehicle.
The journalists claim that he then told a US soldier to start the vehicle's engine and proceeded tell the suspect that unless he talked he would be dragged along the ground.
They ran the engine of the stationary vehicle for about two minutes before untying the prisoner, the report said.
The article in Focus was accompanied by a photo of a man tied to a vehicle while a soldier stood nearby.
US military officials said the allegations were being investigated.
"This alleged behaviour goes against everything the US military stands for and believes in," said Army Col Martin P Schweitzer.
"We take these accusations very seriously. The coalition has appointed a senior officer to investigate the allegations in co-ordination with [Afghan National Security Forces] officials and the local community leaders."
In 2005 a US military interrogator was sentenced to five months in prison for assaulting a detainee in Afghanistan who later died.
Sgt Joshua Claus pleaded guilty to maltreatment and assault, and to forcing an inmate to kiss his boots.
He was the sixth US soldier to be convicted following the deaths of two prisoners at the military base at Bagram, outside Kabul, in 2002.