German news organisation Der Spiegel has published photographs showing two US soldiers posing with the corpse of an Afghan civilian they are accused of murdering.
The photos were among several seized by army investigators looking into the deaths of three unarmed Afghans last year.
Five soldiers based at Joint Base Lewis-McChord, south of Seattle, have been charged with murder and conspiracy in the case.
Due to their content, the photographs were placed under a strict protective order that initially prevented even defence attorneys from obtaining copies.
One of the published photographs shows a key figure in the investigation, Corporal Jeremy Morlock, grinning as he lifts the head of a corpse by the hair. Der Spiegel identified the body as that of Gul Mudin, whom Morlock claims to have killed with Private 1st Class Andrew Holmes on January 15 2010 in Kandahar province.
Another photo shows Holmes lifting the same corpse by the hair. His lawyer said he was ordered to be in the photo, which was taken while the platoon leader, Lieutenant Roman Ligsay, was present.
Ligsay has asserted his Fifth Amendment right against self-incrimination in refusing to testify in the legal proceedings against his troops.
A third photo depicts two apparently dead men propped against a small pillar. Der Spiegel said the photo was seized from a member of the platoon, but did not involve the deaths being investigated as war crimes. Soldiers have told investigators that such photos of dead bodies were passed around like trading cards on digital storage devices.
"Today Der Spiegel published photographs depicting actions repugnant to us as human beings and contrary to the standards and values of the US Army," the army said in a statement released by Colonel Thomas Collins. "We apologise for the distress these photos cause."
The killings occurred during patrols in January, February and May 2010. After the first death, one member of the platoon, Specialist Adam Winfield, sent Facebook messages to his parents, telling them his colleagues had slaughtered one civilian, were planning to kill more and warned him to keep quiet about it.