Policeman claims doctor gave Michael Jackson powerful anaesthetic

Police are working on the theory that a powerful anaesthetic caused the pop star's heart to stop (GETTY IMAGES)

Police investigating the death of Michael Jackson believe that the singer's personal doctor administered a powerful anaesthetic that they think killed him, it was reported today.

A law enforcement official, speaking under the condition of anonymity, told the Associated Press that Dr Conrad Murray gave Jackson propofol to help him sleep hours before his death.

Police are working on the theory that the drug caused the pop star's heart to stop. Dr Murray's lawyer Ed Chernoff has publicly stated that his client "didn't prescribe or administer anything that should have killed Michael Jackson."

Asked about the latest allegations, Mr Chernoff said: "We will not be commenting on rumours, innuendo or unnamed sources."

Last week, officials from the Drug Enforcement Administration raided the doctor's office in Houston, Texas.

They spent two-and-a-half hours at the clinic, leaving with 21 documents and a "forensic image" of a computer hard drive.

Dr Murray served as Jackson's personal physician and was with him when he died.

The doctor has been interviewed a number of times by police in Los Angeles as part of their investigation, but he has not been named as a suspect.

But court reports have identified the 51-year-old physician as the subject of a manslaughter investigation.

The drug he allegedly administered, propofol, lowers the recipients heart rate and blood pressure. It is usually only used in hospitals because of the risks involved.

A safety warning on the drug's label states that the patient must be monitored at all times. Furthermore, equipment to aid breathing and provide artificial ventilation and oxygen "must be immediately available".

The official told the Associated press that Jackson enlisted a number of doctors to administer propofol via an intravenous drip. They added that on June 25, the day the singer died, Dr Murray gave him the drug sometime after midnight.