The Revenue's Customs Service has revealed that it recently uncovered a poitín-making facility close to Ballyconnell in Co Cavan.
The discovery of the fully-operational distilling unit was made last Friday.
Officers took away approximately 2,000 litres of alcohol liquid wash, which is used during the distilling process.
They also found 900 empty bottles, two copper cylinder tanks complete with fittings, seven 200-litre barrels and one pump.
One Irish man in his 40s is being questioned and investigations are ongoing.