Jackson then went into cardiac arrest within 20 minutes of that injection, while Murray had stepped out for a bathroom break, the doctor told authorities in an interview a few days after the death.

By Murray's own account to police, he did not call for help until 12:22 pm, more than an hour after he realized Jackson wasn't breathing.

Propofol is a powerful anaesthetic used to render patients unconscious before major surgery. Medical experts say it should only be used and administered by trained staff under hospital conditions.

Unsealed court documents which included a review of toxicology results found that Jackson died because of "lethal levels of propofol."

The circumstances surrounding Jackson's demise have renewed attention to the issue of prescription drug abuse by celebrities, which was also blamed for the 2007 death of former Playboy model Anna Nicole Smith.

Smith's boyfriend and two doctors are currently facing trial in California, accused of conspiring to provide the sex symbol with prescription drugs.