Police got an emergency call around 4 a.m. from an OnStar-style alert system that calls emergency officials when there is a problem with the vehicle that may require assistance, Officer Wendy Reyes said.

At about the same time, Sheen called police to say his four-door Mercedes-Benz had been stolen, Officer Bruce Borihanh said.

Police and firefighters found the car 300 to 400 feet down a cliff, upside-down in the brushy ravine.

They searched the area on foot and with an infrared-equipped helicopter but found nobody in or around the car, Borihanh said.

"They've looked all around the hillside. There's nobody in the car, nobody around (and no) evidence of anybody being around at the moment of impact," he said.

Sheen was not believed to have been in the car because he would have been badly injured in the accident and "I don't know how he would have gotten back up" the cliff, Borihanh said.

"It's being treated as an auto theft investigation," he said.

Calls to Sheen's publicists seeking comment were not immediately returned.

Sheen, 42, the star of the CBS comedy "Two and a Half Men," was arrested after a Christmas Day domestic disturbance at his Aspen home. A police officer's arrest affidavit quoted his wife, Brooke Sheen, as saying the actor pinned her on a bed while holding a knife to her throat.

Sheen denies threatening his wife. He's scheduled to be arraigned Monday in Aspen on domestic violence charges. He and his wife also are seeking modification of an order that prevents them from communicating with each other. She has said they love each other and want to reconcile.

/CBS News/