Michael Jackson's autopsy revealed no signs of "foul play".
A spokesman for the Los Angeles County coroner said there was nothing suspicious about the pop icon's death but revealed further tests would be needed to determine his cause of death.
Samples have been sent for toxicology tests, but the results could take up to eight weeks.
The spokesman said: "At that time, once those test results have been completed, we anticipate being able to close the case and issuing a final cause of death.
"Based on the autopsy, there was no indication of any external trauma or any indication of foul play on the body of Mr. Jackson."
Investigators were reportedly surprised by how healthy the star - who died on Thursday (25.06.09) after allegedly suffering cardiac arrest at his Los Angeles home - was.
A source told FOX News the body was "stronger than expected", but with significant scarring on the face.
He had bruises on his chest consistent with someone trying to revive him, but there were no obvious signs of a heart attack, leading medical examiners to believe his heart could have been stopped by drugs.
The source also claimed that before and after the autopsy, the body was kept in a private locked crypt so that no photos of the singer without make-up could be leaked.
Jackson's body was returned to his family last night (26.06.09). They have taken it to an undisclosed mortuary.
The 'Thriller' singer's first wife Lisa Marie Presley has revealed Jackson often thought about death and even compared himself to her late father Elvis.
She wrote on her MySpace blog: "He said to me, 'I am afraid that I am going to end up like Elvis Presley, the way he did.'
"I promptly tried to deter him from the idea, at which point he just shrugged his shoulders and nodded almost matter of fact as if to let me know, he knew what he knew and that was kind of that."
Priscilla also spoke about her battle to save him from his "self-destructive behaviour".
She wrote: "I became very ill and emotionally/spiritually exhausted in my quest to save him from certain self-destructive behaviour and from the awful vampires and leeches he would always manage to magnetise around him."
Meanwhile, outspoken comedian Sacha Baron Cohen has paid his respects to Jackson by deleting a scene starring the singer's sister La Toya from his latest film 'Bruno' because it joked about the late star.
Fans with tickets for Jackson's 50 sell-out concerts at London's O2 arena should get a full refund if they bought from the venue or authorised agencies.
Those who purchased from private sellers on websites like eBay might have to rely on the seller paying them back.
A spokesman for concert promoter AEG Live said: "Full ticket refund information and procedures will be released early next week."
A spokeswoman for eBay said people paid using PayPal were covered by insurance, but those who paid by debit or credit card could not claim compensation.
Police are still investigating Jackson's death, and have reportedly "seized bags" of prescription drugs from the singer's home.