What is the Shariah ruling on performing prayers (the five daily prayers and the funeral prayer) in a mosque that was connected to a grave within its structure, from which the bones have been removed, but it is unknown whether they were returned to it or not?

If the grave is outside the mosque, it is permissible to perform the five daily prayers and funeral prayers in it, regardless of whether one knows if the bones were returned to the grave after excavation or not. Scholars have differed regarding the impermissibility of praying in a mosque that contains a grave, and the preponderant opinion is that it is impermissible.