Four men have been arrested following the discovery of a diesel laundering plant in Co Meath.
Customs officers and gardaí carried out a search of a remote building at Knightstown, between Nobber and Navan, this morning.
The raid was the latest in a series of operations around the border and midlands targeting diesel laundering facilities.
Officers seized 30,000 litres of laundered fuel, 12,000 litres of 'sludge', two tanker trailer units and four vehicles at the plant. Ancillary equipment was also dismantled and seized.
The plant had the capacity to launder an estimated 7.8 million litres of fuel per annum with a potential loss to the Exchequer of approximately €4m a year.
Two of the men are from Northern Ireland, one is from Co Meath and the other is from Co Louth.
The laundering procedure involves removing dye from cheap agricultural diesel and the 'washed' product is then sold on as ordinary road diesel.
However, the process creates highly toxic sludge which is usually dumped and the 'washed' diesel can result in damaged engines.
