Drugs officers investigating Michael Jackson's death have raided the Houston clinic of his former doctor for evidence of manslaughter.

A team of 20 officers from the Drugs Enforcement Agency and two robbery-homicide detectives from the Los Angeles Police took part in the sweep at the Armstrong Medical Clinic this morning.

The medical facility is the Houston base of Dr Conrad Murray, who was with Jackson in Los Angeles when he suffered a cardiac arrest on June 25.

Dr Murray’s lawyer Ed Chernoff said a search warrant authorised detectives to “seize items, including documents, they believed constituted evidence of the offence of manslaughter”.

The agents left with a "forensic image" of a computer hard drive and 21 documents, Mr Chernoff said.

He added: "None of the documents taken had previously been requested by law enforcement or the LA Coroner's office."

Dr Murray’s spokeswoman had earlier told the BBC the raid "was a surprise to us and it was a surprise to the attorneys".

Meanwhile, it has been confirmed that police have requested a third interview with Dr Murray, who is not considered a suspect in Jackson's death.

The police investigation has come to focus on the singer’s alleged addiction to prescription medication.

Dr Murray’s lawyer has already denied US media reports that claimed his client had injected the star with a drug similar to morphine in the hours before his death.

The Los Angeles Coroner's office has deferred Jackson's cause of death pending the results of toxicology tests.

(by Jason Gregory)