PHILADELPHIA (CBS) – Philadelphia Police are investigating one of their own after a woman claims she was sexually assaulted in the back of a squad car.

A 32-year-old woman claims she was waiting for a bus at 52nd and Market Streets. When a bus was nowhere in sight, she spotted a police officer and flagged him down.

“He stops, I’ll give you a ride, she gets in the car,” Commissioner Charles Ramsey explained.

According to the woman, that was around 4 a.m. Thursday. She told investigators, instead of helping her get home, the officer attacked her.

Commissioner Ramsey said, “The officer allegedly pulled into Cobbs Creek, a location in Cobbs Creek where the woman claims she was sexually assaulted.”

Sources say the woman told investigators the officer forced her to perform a sex act then dropped her off at the 69th Street Terminal. That’s where the woman stopped a transit officer to report the attack.

As a result of the allegations, Eyewitness News has learned the patrol car reportedly used in the attack is being searched and DNA evidence collected.

“And we’re going rush the DNA to see whether or not we have a match,” Commissioner Ramsey added.

Eyewitness News is withholding the name of the accused officer. Commissioner Ramsey did confirm the officer has been with the department for four years. At the time of the alleged assault, he was on duty, in uniform and in a marked vehicle. As is routine, for now, the officer has been relieved from duty pending the outcome of the investigation.

“It’s like every other case, as events and stories unfold, little bits and pieces change, I can only tell you what I know as of now and as of now, that’s the story,” Commissioner Ramsey said.

The District Attorney’s Office is taking over the investigation.

Reported By Elizabeth Hur and Walt Hunter, CBS 3