Michael Jackson's Doctor Says He's Not the Father of Jackson's Kids

The Beverly Hills dermatologist who was by Michael Jackson's side for years sparked a new round of questions after offering a vague denial of reports that he may have fathered the pop icon's two oldest children.

"To the best of my knowledge, I am not the father of these children," Dr. Arnold Klein told ABC News' Diane Sawyer in a "Good Morning America" exclusive. "I can't answer it in any other way. I don't want to feed any of this insanity that is going around."

VIDEO: Arnie Klein talks about reports that hes the biological father of Michael Jacksons kids.Play

US Weekly reported in the days after Jackson's death that Klein, not Jackson, is the biological father of Prince Michael I, now 12, and Paris-Michael Katherine, 11, Jackson's children with ex-wife Debbie Rowe.

Rowe worked for Klein, and it was in Klein's office that Jackson met the woman who would become first a friend, then his wife, then the mother of his two oldest children.

Klein spoke briefly about them with "GMA," remembering one Christmas Eve he spent with Jackson at his home where he was charmed by the singer's "brilliant" children.

VIDEO: Michael Jacksons friend and dermatologst, Arnie Klein.Play

"The kids were so very happy and so beautiful," he said. "Every time they would pass their father they would say, 'I love you Daddy.'"

Klein also denied prescribing Jackson any of the powerful painkillers, including OxyContin and Demerol, that the singer was said to be addicted to. Klein also denied he was one of five Jackson doctors reportedly under investigation in connection with Jackson's death and said he has not even been contacted by Los Angeles police.

He accused the doctors who prescribed addictive drugs for the pop icon of being "criminals."

"I say that anyone who makes someone an addict or gives a person potentially dangerous substances directly to them to use, like propofol is a criminal," Klein told "GMA." "It becomes nothing more than a manslaughter, or something worse than that."

VIDEO: Stars dermatologist: "No matter what he wanted, someone would give it to him."Play

Propofol, known by the trade name Diprivan, was among the drugs removed from Jackson's rented mansion, according to ABC News sources.

Jackson, 50, died June 25 of apparent cardiac arrest.

Jackson was in Klein's office three days before he died and seemed to be in good spirits, contradicting a report by Jackson's nurse Cherilyn Lee who said the singer was in a horrific amount of pain.

"He was not in terrible pain when I saw him. He danced in the office, and he danced for my patients," Klein said. "He was very muscular, and he was very, very happy and dancing."

"I saw nothing at that point that would make me worry whatsoever," he continued. "But I was always concerned about him because I was always worried about other doctors."

Klein said Jackson, like many other rich and famous California patients, had no problem finding a doctor to get whatever he thought he needed.

"No matter what he wanted, someone would give it to him," Klein said. "The very rich and the very poor and the very famous all get the worst medical care."

Klein said that although Jackson did not confide to him a complete list of medications he was taking, he did have a talk about dangerous prescription drugs with the King of Pop many years ago.

In the days before OxyContin was available, Klein said Jackson requested an older painkiller that was more potent that even morphine.

"I said, 'You can't take that. It's poison. Throw that in the trash,'" Klein said. "And I got him to throw it in the toilet."

"But I can't be there every minute," he said. "I wish I could have been there every minute of the day."

Klein said he had sedated Jackson in the past but only with mild drugs during painful treatments.

"There was nothing wrong with the manner I treated Michael, because what I had to do is restructure for an individual who had lupus, who had terrible acne scarring his face," he said. "But I was not one of the doctors who participated in giving him overdoses of drugs or too much of anything. In fact, I was the one who limited everything, who stopped everything."

But someone apparently was giving Jackson something more powerful, something that could have ended the singer's life.

Jackson Dermatologist Says He's Not Under Investigation

ABC News has confirmed reports that Jackson's arms were found during the autopsy to be marred with track marks consistent with intravenous use of Diprivan, most commonly used to put hospital patients to sleep in the operating room or an intensive care unit.

Toxicology reports were not due to be released for four to six weeks. The cause of Jackson's death on his death certificate was listed as "deferred."

Klein first met Jackson more than two decades ago and was not just his doctor, but a close friend.

But what he did want to do was set the record straight about some rumors that were very painful to Jackson over the years, including that he purposely lightened his skin so he no longer looked black.

Jackson Battled Lupus, Vitiligo, Rumors

Klein said it was he who diagnosed Jackson with lupus and saw growing evidence of vitiligo, both autoimmune diseases that affect the skin.

"It blew me away because here I'm diagnosing the most famous person in the world ? with a very serious ailment," he said.

As Jackson's skin started to be marked with "severe speckling," Klein said, something had to be done even out the tone.

"At the same time he was in the hands of plastic surgeons who didn't know when to stop," Klein said. "But he felt he was a piece of art, that his face was a piece of art."

Klein said he was stunned by the news of his friend's death, sitting in one spot for hours, saying he "went to almost instantaneous shock."

"I feel horrible for what happened because I really, really love this person, because he was the person who was the consummate entertainer, that could get up on a stage and sing. And once he began entertaining, he ... loved every single person in the audience."