Legal Question in Wills and Trusts in California

That depends. Is your father deceased also? Did your father leave a will? If so, who are the beneficiares under the will.Does the will address this issue? Are there any unpaid obligations to the unknown child? If there is an intestacy ( ie no will and the state law governs), is your father in California or another state? Is there any proof the child is a descendent of your father?

You really need to engage counsel who can review the requirements and address the issues with you.

If your father is intestate (having no will) the out of wedlock child may have a claim against his estate. If your father is still alive, he should consult a lawyer to make sure his wishes are carried out.