A person attributing his sister's son to himself after his father's murder

Q: I am from Afghanistan. My brother-in-law was murdered and left orphan children. Therefore, I adopted one of them in order to bring him with me to KSA. His uncle requested us to send him the boy to America. There is no other way to maintain this young boy except through bringing him here to stay with me. What is the ruling on adopting this boy in my name to be able to bring him here? I appreciate your guidance, may Allah reward you.

A: It is not permissible for you to attribute your sister's son to you because this is a lie (Part No. 20; Page No. 377) and will lead to confusion of lineage. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.