An Afghan detainee who died in military custody was injured so severely that his leg muscles were split apart, an Air Force medical examiner testified Tuesday in the trial of a soldier accused in the beating.

Lt. Col. Elizabeth Rouse, who performed the autopsy on the prisoner known as Dilawar (search), said his muscles were "crumbling and falling apart."

She testified that the injuries could have been caused by repeated knee strikes or by a fist.

Rouse also reviewed the autopsy of a man known as Habibullah and said he suffered what appeared to be similar blunt injuries.

Army Pfc. Willie V. Brand (search), 26, an Ohio reservist, is accused of abusing the two prisoners in 2002. Both later died.

The defense has said Brand was ill-trained for his duties and was simply following orders. Prosecutors say Brand was never taught or ordered to abuse prisoners.

Several other soldiers charged with mistreating detainees at Bagram airfield (search) in Afghanistan have pleaded guilty or announced their intention to do so.

No officers in charge of training soldiers involved in the abuse cases or those who oversaw operations at the airfield have been charged. Military officials have said the investigation is continuing.

Before the prosecution concluded its case Tuesday, the jury also heard from three military criminal investigators who interviewed Brand several times.

Each told the jury that Brand said he used knee strikes to gain control of the detainees, whom he described as combative.

Brand's civilian lawyer, John P. Galligan, said he was not sure if he would put any witnesses on the stand when the trial resumes Wednesday.