Three men have been arrested after an oil laundering plant was discovered in Castlefin, Co Donegal.
Officers from Revenue's customs service, assisted by gardaí, discovered the plant this morning.
It had the capacity to launder about three million litres of fuel a year with a potential loss to the Exchequer of €1.3 million..
Some 12,000 litres of laundered fuel, a lorry, a van and a car were all seized.
The men, all from Northern Ireland, are being held at Letterkenny Garda station.