LOS ANGELES — The powerful sedative Diprivan was found in Michael Jackson's home, a law enforcement official said Friday as the city planned for a massive crowd at the singer's memorial service.

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.

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