According to a report on TMZ, Jackson was not the biological father of any of the kids. And Debbie Rowe, the Jackson's ex-wife and mother of his first two children, was just a surrogate - none of her eggs were used. That would mean, technically, that she wasn't the biological mother either.
TMZ cites multiple sources familiar with the births as saying Jackson didn't donate his own sperm for the in vitro fertilization of any of his children. They say Rowe was a paid surrogate who gave birth to son Michael Jr. and daughter Paris.
The report also states that the surrogate for Jackson's third child, Prince Michael II, didn't even know who the receiving parent was.
Jackson's parents have filed for guardianship of the three children in the wake of the pop star's surprising death, though a custody claim by Rowe is still not out of the question. The report notes that because Rowe was married to Jackson at the time of the birth of Michael Jr. and Paris, there is a presumption that she is the biological mother. That would have to be countered by evidence.