In the early morning raid, about 25 officers — including several agents of the Drug Enforcement Administration — scoured the Armstrong Medical Clinic in North Houston, where the physician, Dr. Conrad Murray, keeps an office. Local police officers stood guard outside.

In a statement released shortly after the search began, a lawyer for Dr. Murray, Ed Chernoff, said the agents were executing a warrant that authorized them to "search for and seize items, including documents, they believed constituted evidence of the offense of manslaughter.”

Mr. Chernoff said the agents seized a forensic image of a business computer hard drive and 21 documents.

"None of the documents taken had previously been requested by law enforcement or the L.A. coroner's office,” he said.

It was unclear if the authorities had imminent plans to file charges against Dr. Murray, 56, in connection with Mr. Jackson's death. He is one of several doctors that law enforcement officials are investigating as they try to determine the circumstances surrounding the singer's death.

Dr. Murray, who was with Mr. Jackson when he died, has been questioned by investigators on two occasions, but a spokesman for Dr. Murray said recently that detectives had requested a third interview and asked him to provide additional medical records.

In a telephone interview, Violet M. Szeleczky of the drug administration said the agents — joined by two detectives from the Los Angeles Police Department's homicide division — were executing the search warrant at the request of the Los Angeles police. She declined to elaborate on what the officers were looking for, saying the warrant was sealed.

"This is just a state search warrant," Ms. Szeleczky said, "and we're here facilitating on the request of the L.A.P.D. They came to us for assistance, and we are doing that."

The Los Angeles coroner's office has yet to release the results of a toxicology report.

The clinic in North Houston is owned by Dr. Davill Armstrong, who had his license suspended by the state medical board from 2006 to 2009 for improperly treating 15 patients, and was fined $2,000 in 2008 for allowing his wife to prescribe medication to a patient at the clinic without a physician present.

Dr. Murray, who has an office in Las Vegas, has had numerous legal judgments against him. He was not at the clinic in Houston at the time of the raid.

On Wednesday, a publicist for Mr. Chernoff, Tammy Kidd, said the search "was a surprise" to Mr. Chernoff and his associates.

Mr. Chernoff has said Dr. Murray did not prescribe any drugs that might have caused Mr. Jackson's death. In a statement released Tuesday, he said investigators were seeking "more information" from Dr. Murray, including Mr. Jackson's medical records.

"The coroner wants to clear up the cause of death; we share that goal," Mr. Chernoff said. "We don't have access to the most important information in this case, the toxicology report. We're still in the dark like everybody else. 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."

By noon on Wednesday, the search of Dr. Murray's office had turned into a spectacle. At least eight Houston police vehicles surrounded the clinic, news helicopters hovered above and crowds of onlookers gathered nearby. Federal agents and local officers were seen carting bags of evidence out of the clinic and loading them into the police cars.

(Agencies July 22, 2009)