HELP!! will my boyfriend loose his license for letting an unlicensed driver drive his car?

My boyfriend and his friend were drinking the other night and my boyfriend let his mate drive the car (who only has a provisional licence) Someone reported them for driving carelessly but they were NOT caught in the car when the police got there although they were arrested afterwards down the road a bit. My boyfriend denied driving and was under legal limit and let go but his mate was 3 times over limit and now has been released on bail who also denied driving. The police never seen them in the car but they seem to think they know who it was. What will happen to both of them and my Boyfriends licence? The car has been impounded. Please help answer.. PS WE ARE IN NORTHERN IRELAND.