It's an intravenous drug that's given to people in hospital operating rooms, to knock them out, but it's almost never found in a private home.

According to a law enforcement official, the powerful sedative Diprivan was found in Michael Jackson's home.

A nurse who'd been working with Jackson as he prepared for his comeback concerts had earlier said Jackson pleaded with her for Diprivan, because he was so distraught over his persistent insomnia. She says she refused and warned him the sedative could be deadly.

Authorities are looking into just what drugs Jackson was taking, and whether he had been given them illegally.

An attorney for the doctor who was with Jackson when he collapsed says he's agreed with investigators not to comment until information is released through official channels. The doctor, Conrad Murray, has spoken to police, and authorities say he is not a suspect.