Is it permissible to pray in a mosque that was built and then a grave was placed inside it?

Question:
He says: Honorable Shaykh, may Allah grant you success, if a mosque is built first and then a grave is placed inside it, is it permissible to pray in it?

Answer:
No, it is not permissible to pray in a mosque that is over a grave, whether the grave is the older one and the mosque is new, or the reverse, where the grave is old and the mosque was built over it. This is not permissible because it is taking graves as mosques, and prayer at graves is forbidden. However, they said that if the grave is the older one, the grave should be dug up and the body removed to the cemetery. And if the reverse is the case, where the grave is old and the mosque is new, the mosque should be demolished and the grave left. Yes.