More tests needed to determine Jackson's cause of death

Further tests will be needed to determine whether prescription drugs played any role in Michael Jackson's death, coroner's officials said today, though foul play was ruled out.

As the world mourned the passing of the 50-year-old "King of Pop", police and coroner's officials focused their investigations on the role prescription drugs may have played.

The results of the post-mortem examination were deferred, possibly for between four and six weeks, and attention turned to Jackson's doctor, who was with him when he fell ill.

His personal doctor will now be questioned further by detectives and his car was seized from outside Jackson's house in case it contained drugs or other evidence.

Charlie Beck, assistant police chief of the Los Angeles Police Department, said it was "way too early" to draw any conclusions about the singer's death.

He said officers spoke to the doctor immediately after Jackson's death but now wanted to carry out "an extensive follow-up interview".

Craig Harvey, operations chief of the Los Angeles County Coroner's office, said there was no evidence of foul play or trauma on the superstar's body but further tests were needed.

He said he could not comment on any specific drugs which Jackson may have been prescribed, but added: "We know he was taking some prescription medications."

The post-mortem examination took about three hours and Jackson's body is now available to be released to his family, he said.

Later, a source close to the investigation said Jackson appeared to have suffered a heart attack. A heart attack would not rule out drugs playing a role in his death, but could also indicate a long-term problem such as heart disease.

Jackson, described by many as a misunderstood "genius" and one of the greatest performers of all time, died suddenly on Thursday night, sending the world into mourning.

His death, just days before he was due to start a record-breaking run of 50 shows in London, prompted questions over whether the stress of rehearsals or the singer's use of painkillers could have played any part in what happened.

Brian Oxman, who has acted as the Jackson family's lawyer, said he was concerned about the singer's use of painkillers.

He said: "The issue of pain medication was always being talked about as the number one thing that was getting in the way of him being able to attend the rehearsals."

Jackson's close friend Uri Geller believed it may have been the stress of the singer's London comeback that killed him.

He said: "I guess the stress, the anticipation and the passion he was emitting from his heart, wanting to do this comeback so badly, maybe that got to him.

"That is all I can think, that maybe the stress killed him."

Writer and doctor Deepak Chopra, a friend of Jackson, said the singer approached him in a bid to get prescription drugs.

He said: "In 2005 he asked me for a prescription and that's when I started to get curious about whether he was taking prescription medications and narcotics and the more I probed the more he denied it, but then he admitted he was taking a lot of prescription medication for pain."

He told Sky News Jackson asked him for a prescription for a particular painkiller.

He said: "It was for Oxycontin and it was immediately after the trial. he had a week with me in San Diego.

"When I started probing he started to say 'Well I have a lot of pain, you don't understand'."