A doctor at the Kaiser hospital clinic in Gilroy has been booked on four felony counts of sexual assault involving female patients, according to police.

Raul Ixtlahuc, 39, was arrested Wednesday after an eight-month investigation, said John Sheedy, a Gilroy police detective.

Ixtlahuc, who lives in Salinas, is free on a $250,000 bond, Sheedy said. He apparently has retained an attorney.

Ixtlahuc was not available for comment Thursday.

''The doctor has been placed on administrative leave until the situation is resolved,'' said Michelle Brown, Kaiser communications manager.

Kaiser clinic officials were notified when the investigation of Ixtlahuc began in September, Sheedy said.

All the victims were penetrated during pelvic examinations, Sheedy said.

The doctor is scheduled to appear in court in San Martin May 29 to hear charges against him.