John Gilligan is said to have fled the country under a false identity on Sunday night.
The convicted drug dealer checked himself out of Connolly Hospital in Blanchardstown where he was being treated for gunshot wounds after another failed attempt on his life on the 1st of March.
Sources say that because passengers do not have to give a real name when passing through a port it is the choice of transportation for many criminals fleeing the country.
Conor Feehan from The Herald says he may have left through the Dublin Port but there is no trace of his name:
