An investigation has been launched by Gardaí and the Irish Prison Service into the death of a prisoner at Mountjoy Prison in Dublin.
Colm Carroll, who was serving 16 years for drug offences, was found by prison staff in his single cell just before 1am this morning.
He was taken to the Mater hospital where he was pronounced dead a short time later.
Officers will now await the results of a postmortem to determine the cause of his death.