Diprivan is an anesthetic widely used in operating rooms to induce unconsciousness. Also known as Propofol, it’s given intravenously and is very unusual to have in a private home.

The law enforcement official spoke on condition of anonymity because the person was not authorized to speak about the matter.

A Los Angeles Police spokesman, Lt. John Romero, declined to discuss the case. “It’s an ongoing investigation,” he said.

The cause of Jackson’s death has not been determined. Autopsy results are not expected for several weeks.

At the downtown Staples Center, where Jackson’s memorial will be held Tuesday morning, Assistant Police Chief Earl Paysinger said anywhere from 250,000 to 700,000 people could try to reach the arena, even though only 17,500 tickets will be available.

City Councilwoman Jan Perry urged people to stay home and watch the memorial on TV. There will not be a funeral procession through the city.