A pregnant Marine who vanished last month before she was to testify in a military probe claimed "a senior officer ... had raped her and that the investigation had gone sour," according to new court documents.

The woman made the allegation to her stepmother, who also told investigators looking for the 20-year-old lance corporal that her stepdaughter was bipolar and had a history of compulsive lying, the documents filed this week state.

Military officials said Thursday they had ordered the missing Marine's roommate, Sgt. Daniel Durham, to return from training in California to answer questions about the case.

Durham is believed to be the last person to speak with the lance corporal. He was to return to Camp Lejeune as soon as possible, Onslow County Sheriff Ed Brown said.

Brown did not describe Durham as a suspect, adding that the case remained a missing persons investigation.

"We do feel like he has answers and importance in being back here," Brown said.

According to search warrant affidavits filed this week, the stepmother has told investigators that her stepdaughter "claimed she had been raped by a senior officer at her command, and that the investigation had gone sour."

The Associated Press had identified the missing Marine before the allegations of sexual assault became public. The AP generally does not identify people who allege they are victims of sexual assault.

Brown declined to comment on the rape allegations detailed in the search warrant, as did officials at Camp Lejeune.