The police and federal agents arrived at approximately 10:20am and have swarmed inside the Armstrong Medical Clinic where Murray has his office. Several marked Houston PD cruisers are at the scene and a couple of uniformed officers at the front door of the clinic. A couple of people have been let inside the business, but they have left again after a few minutes.
Law enforcement authorities told ABC News the warrant for the search was based on preliminary results of the autopsy made available to them which indicate Jackson's death was tied to the drug Propofol, a powerful anesthetic normally used only in hospital operating rooms.
Edward Chernoff, who represents the physician Conrad Murray, posted a statement on his law firm's website late Tuesday saying investigators from the Los Angeles County coroner's office have asked for medical records in addition to those already provided by Murray.
"The coroner wants to clear up the cause of death; we share that goal," Chernoff said in his statement. "Based on Dr. Murray's minute-by-minute and item-by-item description of Michael Jackson's last days, he should not be a target of criminal charges."
Murray has emerged as a central figure in the investigation into Jackson's death. The doctor, who had been recently hired by Jackson, was with him in his mansion and tried to revive him.
Although Chernoff has said the doctor didn't give the pop star any drugs that contributed to his death, Murray has nonetheless received attention from those angry over the singer's death.
Police detectives have already spoken to Murray twice -- once immediately after the singer's death and again two days later. Police investigators say Murray is cooperating in their investigation. Dr. Murray's immediate whereabouts are unknown.
A cause of death has yet to be determined for the pop star. The coroner's office is expecting to release autopsy results next week.