THE mystery surrounding Michael Jacksons children took a further twist yesterday, with reports that Debbie Rowe is not the natural mother of the oldest two. It has long been claimed that Jackson was not the biological father of Prince Michael, now 12, and Paris, 11. But the U.S. media yesterday suggested that Miss Rowe, 49, was also merely a surrogate Sources close to Jackson alleged that all three of his children were conceived outside the womb by in-vitro fertilisation. They claimed that neither Jacksons sperm nor Miss Rowes eggs were used. The revelation may, in part, explain Miss Rowes ambivalent attitude towards claiming custody of the children in the aftermath of their fathers death last Thursday. Her lawyer, Eric George, said yesterday that she would decide within the next few days whether or not she would challenge their grandmother Katherine Jackson for the right to care for them. The latest news leaves the older childrens parentage as clouded as that of their younger brother, seven-year-old Prince Michael II, better known as Blanket. And it could mean that the childrens real parents will never be known. Many IVF clinics in the U.S. offer the option of implanting embryos formed from the egg and the sperm of anonymous donors and the identities of the biological parents remain a secret even to the couple who take the baby home. To add to the confusion, the U.S. magazine Us Weekly is also claiming that Arnold Klein, Jacksons Los Angeles-based dermatologist and Miss Rowes former boss, is the real father of the older children. Klein refused to comment, but the magazine quotes a family insider as saying: 'He is the dad. He and Debbie signed an agreement saying they would never reveal the truth. Kleins attorney, Richard Charnley, issued a statement: 'Because of patient confidentiality, Dr. Klein will make no statement on any reports or allegations. 'Like millions of Michaels fans around the world, Dr Klein is saddened by Michaels death and extends his condolences to the family. In the case of Jacksons younger son, the surrogate mother chosen to give birth to him wasnt even told that Michael Jackson was the 'receiving parent, it was claimed yesterday. According to the website TMZ, which broke the story of the singers death, Jacksons lawyer went to the Grossmont Hospital in San Diego three days after the baby was born and picked him up. The custody situation may be confused even further by claims that Jackson never officially adopted his three children, even though he is not their natural father. The star never filed legal papers formalising his role as the childrens guardian, apparently believing there was no third party who would try and contest him for custody. Legal experts claim the courts would probably still consider Jackson the childrens father and that Miss Rowe, who was married to the star at the time of the births, would be considered the mother unless evidence was presented to the contrary. If Debbie Rowe does challenge the Jackson family for custody of the two older children, then the situation could get very messy indeed. 'That may be one reason why Debbie is biding her time. She wouldnt want the children to be dragged through an ugly court battle, said one leading Los Angeles custody lawyer. In court papers filed on Monday, Katherine Jackson said the children 'have no relationship with their biological mother. In past interviews, Miss Rowe has changed her version of what occurred, saying sometimes that Jackson was the biological father of Prince Michael and Paris, and at other times that he was not. - Daily Mail