A judge has ordered the personal doctor of Michael Jackson to stand trial for involuntary manslaughter. Judge Michael Pastor gave the ruling against Dr Conrad Murray at a preliminary hearing in Los Angeles. Prosecutors say that he gave Jackson a lethal dose of a powerful anaesthetic mixed with other sedatives and then failed to provide proper care. Dr Murray, 57, has pleaded not guilty, and says he did not give Jackson anything potentially lethal. Judge Pastor made the order against the cardiologist on the sixth day of the hearing. He also granted a request by the California Medical Board to suspend the licence of Dr Murray to practise in the state. Dr Murray faces up to four years in prison if convicted at trial. 'Becoming addicted' Earlier, Detective Orlando Martinez, who interviewed Dr Murray two days after Mr Jackson's death in June 2009, gave evidence to the court. Mr Martinez told the hearing Dr Murray said that Jackson told him on the day he died he would have to cancel his comeback concerts in London unless he had a dose of the anaesthetic, propofol. The detective said Dr Murray admitted giving Jackson it after a night administering lesser drugs to help him sleep. The doctor said he then left the room for "two minutes" to go to the bathroom, but on returning found the singer had stopped breathing, Mr Martinez said. Dr Murray started to try to resuscitate Mr Jackson but told the detective he did not call for an ambulance himself because "he said he was caring for his patient and he did not want to neglect him". Prosecutors say that phone records show the doctor made a series of other calls before an ambulance was finally called more than an hour later. Mr Martinez also said Dr Murray told him he had given Mr Jackson doses of propofol six nights a week for two months but was trying to wean him off the drug as he feared his patient was becoming addicted. During closing arguments at the hearing, Dr Murray's lawyer, Joseph Low, said the case should be dismissed because prosecutors had not adequately proved how Dr Murray caused Jackson's death. He also said Jackson's health may have been a contributing cause. Source: BBC