MICHAEL Jacksons personal doctor administered a powerful anaesthetic to help him sleep, and authorities believe the drug killed the pop singer, a law enforcement official said this morning. The official, who spoke on condition of anonymity because the investigation is ongoing, also provided a glimpse inside Jacksons rented mansion, describing the room Jackson slept in as outfitted with oxygen tanks and an IV drip. Another of his bedrooms was a shambles, with clothes and other items strewn about and hand-written notes stuck on the walls. One read: children are sweet and innocent. The official said Jackson regularly received propofol to sleep, relying on the drug like an alarm clock. A doctor would administer it when he went to sleep, then stop the intravenous drip when he wanted to wake up. On June 25, the day Jackson died, Dr Conrad Murray gave him the drug through an IV sometime after midnight, the official said. Though toxicology reports are pending, investigators are working under the theory propofol caused Jacksons heart to stop, the official said. Jackson is believed to have been using the drug for about two years and investigators are trying to determine how many other doctors administered it, the official said. Dr Murray, 51, has been identified in court papers as the subject of a manslaughter investigation and authorities last week raided his office and a storage unit in Houston, Texas. Police say Dr Murray is co-operating and have not labelled him a suspect. Using propofol to sleep is a practice far outside the drugs intended purpose. One doctor said administering it in a home to help a person sleep would constitute malpractice. Propofol can depress breathing and lower heart rates and blood pressure. Because of the risks, propofol is only supposed to be administered in medical settings by trained personnel. Instructions on the drugs package warn that patients must be continuously monitored, and that equipment to maintain breathing, to provide artificial ventilation, and to administer oxygen if needed must be immediately available. IOL Dr Murrays lawyer, Edward Chernoff, has said the doctor didnt prescribe or administer anything that should have killed Michael Jackson. When asked about the law enforcement officials statements he said: We will not be commenting on rumours, innuendo or unnamed sources. Dr Murray became Jacksons personal physician in May and was to accompany him to London for a series of concerts starting in July. He was staying with Jackson in the Los Angeles mansion and, according to Mr Chernoff, happened to find an unconscious Jackson in the pop stars bedroom the morning of June 25. Dr Murray tried to revive him by compressing his chest with one hand while supporting Jacksons back with the other. Its unclear how long it took for someone at Jacksons home to summon paramedics, though Dr Murrays own lawyers have said it was up to half an hour. Paramedics arrived about three minutes after they were called and tried to revive the music superstar for another 42 minutes before sliding him into the ambulance and racing with lights flashing and siren blaring to UCLA Medical Centre, where Jackson was pronounced dead. Authorities arrived at the singers house after the death and found a chaotic scene. The top floor had been all but sealed off, with only Jackson, his children and Dr Murray allowed upstairs, the official said. Jacksons bedroom was a mess, with items seemingly thrown about and some 20 hand-written notes stuck on the walls. A porcelain girl doll wearing a dress was found on top of the covers of the bed where he slept, the official said. The temperature upstairs was stiflingly hot, with gas fireplaces and the heating system on high because Jackson always complained of feeling cold, the official said. Police found propofol and other drugs in the home. An IV line and three tanks of oxygen were in the room where Jackson slept and 15 more oxygen tanks were in a security guards shack, the official said. Cherilyn Lee, a registered nurse who gave Jackson nutritional counselling and vitamins earlier this year, said he complained of insomnia and asked her repeatedly for Diprivan, the brand-name version of propofol. Ms Lee said she warned him of the drugs dangers and rejected his requests. Los Angeles police interviewed Dr Murray twice soon after Jacksons death. Last week, detectives flew to Houston and, along with federal drug agents, searched a medical clinic he ran and a storage unit he rented. They seized a long list of items, including the contents of three computer hard drives, two emails from his administrative assistant at the Las Vegas practice Dr Murray ran and various other documents. A sealed search warrant approved by a Houston judge and later made public 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 offense. IOL