A detainee alleges that while in US custody he was assaulted during interrogation. The investigation established probable cause to believe detainee was assaulted during interrogations at an unknown location by unknown individuals. Detainee was held at Camp Cropper but was removed for ten (10) days to unknown location where he was abused. After he was returned to Camp Cropper, he was treated medically for abrasions and injuries. There was no documentation found that identified the individuals who removed the detainee from Camp Cropper and possibly abused him.