Police are searching for a Dublin doctor who they say sexually battered two men at his home and took hundreds of photographs of 19 patients who were unconscious and undressed at his medical clinic.

Dr. Tony Shiu, who ran a private practice in Dublin, is being sought on a $1 million warrant. He disappeared after the warrant was issued early last month, and police believe he has left the Bay Area.

The doctor allegedly drugged two men at his Dublin residence in August and then raped one of them, Dublin police Sgt. Herb Walters said.

A search of his home turned up about 450 photos of 19 male patients who were unconscious and semi-nude in medical examination rooms, Walters said.

Police have been unable to contact Shiu through his cell phone, and family members have said they don't know his whereabouts, Walters said.

Shiu graduated in 1994 from UC Davis School of Medicine and served his residency at Kaiser Hospital in Oakland, according to public records. Before starting his private practice about three years ago, Shiu worked at a ValleyCare clinic in Livermore, Walters said.

The doctor came under suspicion after the two alleged victims reported to police that Shiu had drugged them as they visited his home on Aug. 18. One of the men had known Shiu for years; the other met him that night.

The men said they met Shiu at his home and planned to meet other friends in Oakland and Emeryville for a night out in San Francisco. They each had two alcoholic drinks shortly after arriving at the house and then lost recollection of the rest of the night, Walters said.

"Witnesses told us that they made it to Oakland and Emeryville, but that the two men were too far out of it to continue to San Francisco," Walters said.

It is believed that Shiu drove them back to his residence at that time, Walters said.

After waking up the next morning with no memory of the previous evening, the men became suspicious and had themselves examined at a local hospital. They tested positive for benzodiazepine, a drug commonly prescribed for anxiety and whose side effects include memory impairment, confusion and lightheadedness, Walters said.

Police ordered further tests, which showed that one of the men had been raped, Walters said.

Police obtained search warrants for Shiu's home and found digital photos of the 19 men who were in examination rooms, believed to be at Shiu's clinic and possibly another location, Walters said.

Two of the men have been positively identified.

"You can imagine how shocked they were when we showed them naked pictures of themselves," Walters said.

No other alleged victims have come forward, he said.