What is the status of a child who was born out of wedlock in regard to the inheritance of his father?
A child born out of wedlock can only be the heir of his mother. If the child was born in another man’s house while his mother is married to him, the child becomes heir to that man, even though he is not the biological father.
Since relations out of wedlock are null according to Islamic law, the child cannot become a heir to his biological father or his relatives. Should the father himself desires, he can give the child out of his possessions during his lifetime.