Published: 7:21PM BST 28 Jul 2009  Police outside Dr Murray's Las Vegas home Photo: BIGPICTURESPHOTO.COM  Conrad Murray: Michael Jackson's personal doctor Photo: PA/HOUSTON CHRONICLE  Officials with the US Drug Enforcement Administration were at Dr Murray's Las Vegas home on Tuesday as part of a manslaughter investigation into the singer's death.  Dr Murray, a cardiologist with practices in Las Vegas and Houston, had his Texas office and a storage unit searched last week by DEA agents. Court records show the agents were searching for evidence suggesting that the doctor committed manslaughter.  Police say Dr Murray is cooperating and have not labelled him a suspect.  Investigations into the Thriller star's death have revealed that he relied on a strict drugs regime.  A doctor would reportedly administer the anaesthetic, a strong sedative usually given to patients before surgery, when Jackson went to sleep and turn off the drip when he wanted to wake up.  On June 25, the day Jackson died, Dr Murray gave him the drug some time after midnight, said an official.  Although the authorities are understood to believe that properol was the ultimate killer, Jackson's body contained a lethal cocktail of prescription drugs, including OxyContin and Demerol, ABC News reported.  Edward Chernoff, Dr Murray's lawyer, has said the doctor never prescribed or administered any drug that "should have killed" the star.  He has never said whether the doctor gave Jackson propofol, the brand name of which is Diprivan. Bottles of the drug were discovered at Jackson's home and investigators believe he had been using it for two years.  When asked about the latest claims, Mr Chernoff said: "Things tend to shake out when all the facts are made known, and I'm sure that will happen here as well".  Mr Chernoff has already admitted that Dr Murray did not call an ambulance for 30 minutes after he found Jackson unresponsive and instead tried to resuscitate him. "This doctor is in serious trouble," Roy Black, a criminal defence lawyer, told Good Morning America on Tuesday.  Mr Black said that, if charged, Dr Murray – who was to have accompanied the singer during his London concerts – would have to prove there was a "sound medical reason" to give Jackson a drug intended for use in the operating room.  Toxicology reports are expected later this week but investigators are working under the theory that propofol caused the singer's heart to stop, an official said.  The drug can depress breathing, and lower heart rates and blood pressure. It is so specialised that it is not even covered by US government rules on what doctors can be licensed to administer.
US police searched the home of Michael Jackson's doctor Conrad Murray after it    emerged that the singer died after he was given a powerful, surgical    anaesthetic through a drip-feed to help him sleep.