Golf Rule: Lost Ball Found Plugged - What's the Ruling?

Question
A ball was hit and witnessed by all members of the 4some to have landed in the middle of the fairway. But upon reaching where the ball should of been, was unable to find the ball. Player, after looking for the ball for the required time, returns to tee and re-hits. First ball was then found to be plugged. What is the ruling for finding the plugged ball, after hitting the second ball?

Answer
If you looked for the ball for 5 minutes and it wasn't found then i'm afraid it is deemed to be lost. If you searched for a few minutes then went back to the tee and re hit, if you didn't say "provisional" then it becomes the ball in play, if the ball was found on your way back to the tee then you can play your first.