If someone is found alive in their grave after having been washed and prayed over, then dies while still in the grave, must they be washed and prayed over again?

This Ghusl (ritual washing) and prayer did not occur in their proper place, as they were performed on someone still alive. They must be redone when death is confirmed. It is necessary to verify a person's death before applying the rulings pertaining to the deceased, especially if they were drowned or epileptic.