ET special correspondent Diane Dimond has the latest on the anesthesia drug reportedly found at Michael Jackson's home.

Propofol, also known as Diprivan, is speculated to be what triggered the King of Pop's cardiac arrest. Thousands of vials of propofol have been recalled after testing confirmed that two lots of the drug may be tainted.

Diane has the latest on "The Propfol Trace."

"The trail is narrowing. The clock is ticking. All Propofol bottles come with lot numbers on them and within that lot number there can be thousands of bottles," Diane says. "That doesn't mean you can't trace them but it could just take longer."

The biggest key to the puzzle of Michael's death will be revealed when the L.A. Coroner's Office releases its autopsy toxicology report in the coming weeks.

"My sources tell me the coroner's office knows right now what killed Michael Jackson, and one of the clues was his hair," Diane says. "Hair samples can tell pathologists what drugs someone was on and how long they took them. Jackson's brain tissue can reveal everything from past physical abuse, to drug overdoses and when they actually occurred."

Also weighing in on the investigation into the death of the King of Pop is Tokyo-based Dr. Eugene Aksenoff, who claims the star asked him for amphetamines during a trip to Japan in 2007. But Dr. Aksenoff says he refused to prescribe them.

"I made it absolutely clear, no narcotics!," he says. "If you will start you will not ... you will live only at the longest three years!"

Keep checking back for the latest in the Michael Jackson investigation. And watch ET tonight for more of Diane's report.