SAN DIEGO -- The aftermath of Michael Jackson's death has now shifted focus to his three children. Whoever becomes their legal guardian stands to gain significant control over Jackson's estate until the children turn 18.

10News I-Team reporter Mitch Blacher, who was the first local reporter to confirm one of Jackson's sons was born in San Diego, obtained a copy of Prince Michael Jackson II's birth certificate.

The document shows that Jackson's youngest son was born at Grossmont Hospital but it doesn't list a mother, only Michael Jackson as the boy's father.

Jackson's will -- drafted in 2002 -- reportedly divides his estate between his mother, three children and several charities. But the children could not legally take ownership until they turn 18, meaning their current legal guardian would control their share until then.

Sources told 10News that Jackson is not the biological father of any of the three children. That has raised questions about who might want to claim parental rights.

Reproductive lawyer Theresa Erickson said the law is clear. "They [the couple giving a baby up for adoption] didn't have to know who they were donating to, it could have been anonymous. If they didn't make a challange the court will find that they have no right at all whatsoever."

Jackson's 79-year-old mother Katherine currently has custody but, Erickson said, the surrogate mother of Jackson's first two children, Deborah Rowe, might have a strong case for custody.

"If she's listed on the birth certificate she could have a challange," Erikson said.

However, in a 2001, child custody hearing with Jackson, Rowe stated, "I had the children for him. I did it for him to become a father not for me to become a mother. You earn the title 'parent.' I have done absolutely nothing to earn that title."

Erikson said, "If she said, 'I didn't earn the right, I didn't want to be a parent,' remember those statements were said when he was alive. Now that he's dead it's a totally different situation."

As for the child born in San Diego, Prince Jackson II's birth certificate does not list a mother it only says Michael Jackson is the legal father. Erickson said even if Jackson isn't the biological father and didn't adopt any of his children, as long as his name is on the birth certificate a court will see him as the legal father.

"The fact that he didn't do an adoption is irrelevent because this is actually the legal way to do it, to put his name on the birth certificate as the sole parent," Erikson said.

One of the reasons there's so much speculation over a custody battle is Jackson's net worth is estimated at $236 million.

If his will stands up, a third of that will go to his kids.