Michael Jackson's personal doctor is the target of the manslaughter investigation into the singer's death, according to court documents.
The documents were filed yesterday, the day after agents seized items from Dr Conrad Murray's clinic in Houston, Texas, it emerged today.
A search warrant approved by a Houston judge allowed authorities to seek "property or items constituting evidence of the offense of manslaughter that tend to show that Dr Conrad Murray committed the said criminal offence".
A receipt for the search warrant detailed items seized when government drug agents and Los Angeles police descended on Dr Murray's clinic on Wednesday. Among them were 27 tablets of the weight-loss drug phentermine, a tablet of the muscle relaxant clonazepam, two hard drives, tax notices and a controlled substance registration.
Dr Murray's lawyer, Edward Chernoff, referred queries to the statement he made a day earlier in which he confirmed a search warrant had been executed and that none of the items seized had previously been requested by authorities.
Los Angeles Police Department spokesman Officer Bruce Borihanh said a search warrant was served but had no other comment.
Cardiologist Dr Murray was hired as 50-year-old Jackson's personal physician not long before the pop megastar died.
He was in Jackson's rented Los Angeles mansion when the singer was found unconscious on the morning of June 25 and tried unsuccessfully to revive him.
An official determination of what killed Jackson willl not be made until at least next week, when the Los Angeles County coroner expects to have a completed toxicology report.
Jackson had a long history of prescription drug use and investigators are speaking with a number of doctors who treated him. Propofol, a powerful anaesthetic, has emerged as an important part of the investigation. Doses of it were found in his mansion, according to a person with knowledge of the investigation.
Propofol was not listed on the receipt of items filed in the search warrant, which was approved on Monday by Harris County District Court Judge Shawna Reagin. The warrant was under seal when it was executed on Wednesday; its contents were revealed yesterday when the receipt was filed with the court.
A second search warrant, also executed on Wednesday, targeted a storage locker Dr Murray rented about five miles from the north Houston clinic. Los Angeles police officers and agents from the Drug Enforcement Administration searched the 10x15ft unit, said Sue Lyon, general manager of West 18th Street Self Storage.
Ms Lyon said she did not know what was taken, though she did notice authorities gave two itemised sheets of paper to Dr Murray's lawyers who were present.
"It was basically all secretive, and nobody put their nose in nobody's business," Ms Lyon said.
Murray rented the unit on 1 April, according to Ms Lyon, and while he never visited it personally, others from his clinic did six times - the last time on the morning of Jackson's death.