Michael Jackson's long-time dermatologist Dr. Arnold Klein said he was aware that Jackson took dangerous drugs and warned him repeatedly about the powerful drug Diprivan which the pop star used to fall asleep.

Diprivan, also known by the generic name Propofol, was administered to Jackson through an anesthesiologist that traveled with him on tour, he said. The drug is administered intravenously to induce or maintain anesthesia or sedation. The specific year or tour in which Michael Jackson took this drug wasn't detailed.

I knew at one point that he was using Diprivan when he was on tour in Germany, Klein said Wednesday on CNN's Larry King Live. I told him he was absolutely insane. I said, 'You have to quit it. This drug, you can't repeatedly take.'

Klein also said Michael at one time had an addiction. He went to England and withdrew from that addiction in a secure setting where he went off drugs all together, he told Larry King yesterday.

Klein denied he ever gave Jackson drugs beyond the doses needed for surgery. If you took all the pills I gave him in the last year at once, it wouldn't do anything to you.

The cause of Jackson's death in June 25 is pending. A toxicology report and police, State attorney general's office and the U.S. Drug Enforcement Administration are investigating it.