An official familiar with details of the investigation in Iraq has told reporters that a flammable liquid was used to burn the rape victim's body in an attempted cover-up.

The affidavit noted that prosecutors have photos taken by Army investigators in Iraq of all four bodies found inside a burned house and a photo of a burned body of "what appears to be a woman with blankets thrown over her upper torso."

The age of the young woman was unclear. FBI documents estimated her age at 25, but a neighbor of the family said the rape victim was 14 and her sister was 10.

The Washington Post reported the rape victim was 15 and that her mother worried her daughter had attracted the attention of US soldiers at a checkpoint. The mother asked a neighbor if the girl could sleep at his house.

The neighbor agreed but the girl and her family was attacked the next day, according to the Post. The neighbor told the Post he was one of the first people to arrive at the house after the attack and found the girl dead in a corner, her hair and a pillow burned and her dress pushed up to her neck.

Green, who was arrested Friday in the town of Marion northwest of Charlotte, is being prosecuted in federal, rather than military court because he is no longer in the Army. According to the affidavit, his 11-month-stint ended "before this incident came to light" when he was given an honorable discharge "due to a personality disorder."

The soldiers accused in the rape and killings are from the same platoon as two soldiers whose mutilated bodies were found June 19, three days after they were abducted by insurgents near Youssifiyah, southwest of Baghdad. Military officials say they believe guilt over the mutilations may have spurred a confession by one of the soldiers during a combat-stress debriefing late last month.

No other soldier has been charged in the case, said Maj. Joseph Breasseale, a US military spokesman in Baghdad. However, military officials have said four Army soldiers have had their weapons taken away and were being confined to their base near Mahmoudiya.

The mayor of Mahmoudiya, Mouayad Fadhil, said Monday that Iraqi authorities had started their own investigation. He said US Army officers were also seeking permission to exhume one of the bodies; the US military declined to comment on the report because the investigation is ongoing.

According to the affidavit, Green was arrested while traveling back to Fort Campbell after attending a funeral for one of the mutilated soldiers in Arlington, Va.

He was quoted in December by the Fort Campbell Courier about a search for insurgents and expressed surprise at the ease of the mission.

"I was surprised by how many people weren't home, but the ones who were there were submissive and let us look through their things," he said.

Court officials said Green will have a preliminary hearing and a detention hearing on July 10 in Charlotte, and will then be brought to Louisville to stand trial.