Michael Jackson used to be married to Debbie Rowe, but neither were the biological parents of the singer's first two children, Michael Jr., 12, and Paris, 11.
Their father is Arnold Klein, Jackson's L.A.-based dermatologist and Rowe's former boss, multiple sources confirm to celebrity gossip magazine Us Weekly.
"He is the dad," says an insider of Arnold Klein, who has not commented. "He and Debbie signed an agreement saying they would never reveal the truth."
While Debbie Rowe and Michael Jackson never confessed to their kids' true lineage, she did admit in 2002 that she carried his children as a "personal favor."
Neither has confirmed that the marriage was ever consummated.
"I said, 'Let me do this. You need to be a dad. You have been so good to me,'" Rowe - who met Jackson when she was a nurse's assistant in the 1980s - has said.
News that Michael Jackson is not the biological father of any of his kids surfaced earlier today. Now we've learned he never legally adopted them either.
Neither Jackson nor Debbie Rowe are the biological parents of Michael Jr. and Paris. Nor is Michael the biological parent of Prince Michael Jackson II.
Jackson never filed legal papers to adopt any of his children. Legal experts say Jackson would be presumed the father but it's not conclusive by any means.
As for why Jackson didn't formally adopt them - some speculate at the time they were born, there was no third party he though would try to claim custody.
Jackson apparently never thought Rowe would mount a custody battle, which wasn't totally absurd, as she actually tried to give up all rights to them once.
However, the music icon's death at the age of 50 last Thursday, along with today's developments, has everyone guessing where the children will end up.
Michael Jackson Jr., Paris Jackson and Prince Michael Jackson (Blanket).