More than 23,000 litres of beer has been seized at Dublin Port.
Revenue officers found the alcohol without correct papers in a truck that arrived from Holyhead this morning.
A man in his thirties has been questioned about the haul, believed to be worth more than €100,000.
That represents a potential loss to the Exchequer of approximately €53,000.
In a separate operation in Wexford Town on Monday, 14,500 unstamped cigarettes were seized at a house.