ET's Kevin Frazier exclusively sits down with Michael Jackson's former dermatologist Dr. Arnie Klein, who says he warned Michael about the dangers of the powerful drug that allegedly led to his death.

"I told him that it was very dangerous. I told him it was addicting. And, I told him that he really shouldn't be using it," Klein says he told Michael about Propofol.

Klein says he didn't know Jackson was allegedly using Propofol around the time of his death, but he says Jackson had told him in years past that he'd used the drug.

"I knew that he had over-used Profol because in Germany on a tour, he told me that he was using Propofol. And I know that he had a bag of Propofol and called me one night and wanted me to start, and I told him how insane he was and went out there and told him, 'You can't start doing this.'"

Click the video for more of Kevin's interview with Dr. Klein.