Michael Jackson's doctor told police he had given the singer Propofol six nights a week for months before he died.

A preliminary hearing into the cause of the 'Thriller' singer's death heard testimony from Los Angeles police detective Orlando Martinez yesterday (11.01.11), who said that in interview the singer's personal physician, Dr. Conrad Murray, admitted he had been giving the later singer the powerful anaesthetic for two months before his death.

Michael was found dead from acute Propofol intoxication at his rented Los Angeles house on June 25 2009, while he was under the care of Dr. Murray - who has pleaded not guilty to involuntary manslaughter.

The doctor told police he was worried the 'Thriller' singer had become addicted to Propofol - a powerful anaesthetic, not usually used outside hospitals - and had started to wean him off it two nights earlier.

According to the police interview with Dr. Murray, on the day of Michael's death he had administered 25 milligrams of the anaesthetic - about half the usual dose at around 10.40am, after the singer had complained about not being able to sleep ahead of rehearsals for his scheduled 50 comeback shows in London.

Orlando quoted Murray as saying: "Mr. Jackson began to complain that he couldn't sleep and that he would have to cancel his rehearsal and cancel his shows if he couldn't get any sleep since he couldn't perform."

Dr. Murray said after giving the dose of Propofol, he only left Michael alone for two minutes before returning and realising he wasn't breathing. However, the prosecution say emergency services show he didn't call paramedics until 12.21pm.

When questioned by police as to why he said this was, Orlando said: "He said he was caring for his patient and he did not want to neglect him,"

Earlier in yesterday's hearing, pharmacist Tim Lopez, owner of Applied Pharmacy Services in Las Vegas, where Murray has a clinic, testified to having supplied the doctor with 255 vials of Propofol during the three months before the singer died.

The four shipments of Propofol were purchased between April 6 and June 10, 2009, with most of the drugs shipped to the home of Murray's girlfriend in Los Angeles.

One of the key points the prosecution are hoping to convince the judge of is that the doctor was distracted when he should have been monitoring the singer but they claim he sent emails and made phone calls after administering the drug.

Earlier in the hearing, waitress Sade Anding testified she had been on the phone with the doctor at 11.57am, when he realised something was wrong.

She said: "I didn't hear him on the phone anymore. I heard commotion as if the phone was in a pocket, and I heard coughing, and I heard a mumbling of voices."

The hearing seek to establish there is enough evidence for Dr. Murray to face a full trial for involuntary manslaughter and will continue later today (11.01.11).