Q: About 20 years ago, my sister married a man and I was young at that time. She immediately became pregnant, but only Allah knows if the child was from her husband or someone else. Consequently, the husband disowned the child and they were referred to the courts where they were given a legal ruling. There were witnesses and Li`an (allegation of adultery against a wife, accompanied by mutual invoking of Allah’s Curse/Wrath if lying) and the matter was finally resolved. (Part No. 11; Page No. 260) The point is that my father adopted the child and attributed him to his name. Hence, the child became my brother and an uncle of the children of his mother who are actually his brothers and sisters. My father did so with good intentions so that the child would not be taken to a foster care home. He thought that doing so would provide care for an orphaned child. However, the child grew up and is now a young man. My father registered him along with the family and an ID card was issued for him in my father's name. A lot of people do not know that he is not my father's son, and it is known that Islam prohibits giving an orphan one's name.I hope you will explain the proper and legal way to correct the status of the family and safeguard it against mixture of lineages. I told my children that the young man is not related to them, but they find this odd, because he has the same name of our father. I am confused, as my father is still alive and I fear that if we pass away while these young children do not know the truth about him and his offspring as their Mahram (permanently unmarriageable relative) while in fact they have no relation to him. Appreciate your guidance, may Allah reward you with the best.