‘Amr b. Shu'aib, on his father’s authority, told of his grandfather saying

The Prophet (ﷺ) decided regarding one who is treated as a member of a family after the death of his father to whom he is attributed when the heirs say he is one of them, that if he is the child of a slave woman whom the father owned when he had intercourse with her he is included among those who seek his inclusion, but gets none of the inheritance which was previously divided;* he however gets his portion of the inheritance which has not already been divided, but if the father to whom he is attributed had disowned him he is not joined to the heirs. If he is the child of a slave woman whom the father did not possess or of a free woman with whom he had illicit intercourse, he is not joined to the heirs and does not inherit even if the one to whom he is attributed is the one who claims paternity, for he is a child of fornication whether his mother was free or a slave. Abu Dawud transmitted it. *Mirqat 3:506 explains this as a reference to what had happened in the pre-Islamic period.