UPDATE: A man arrested by gardaí in Dungarvan in connection with an alleged assault outside a nightclub in the town has been released without charge.
A man in his thirties suffered head injuries in the incident and is understood to be in a critical condition in University Hospital Cork.
Gardaí and emergency services were called to the scene of an altercation outside a nightclub on Davitts Quay, Dungarvan shortly after 2:00am on Sunday morning.
The injured man was brought to University Hospital Waterford before being transferred to Cork.
A technical examination of the scene has been carried out.
Gardaí are appealing for witnesses to contact Dungarvan Garda Station on 058-48600 or the Garda Confidential Line 1800 666 111.
A file is being prepared for the DPP.