Customs officers have dismantled a sophisticated diesel laundering operation found in Co Louth, just metres from the border.
The laundering had been taking place in a large, purpose-built shed which had been partially sunk in the ground to obscure any observation of what was going on there.
Gardaí say those involved in this factory had invested a large amount of money in its building and equipping.
It is believed the laundering was going on 24 hours a day.
Just after dawn this morning, customs officers - backed up by armed gardaí from the Regional Response Unit - raided the premises close to Hackballscross and arrested one man in his 20s.
Inside was a large tanker which was being used to store and remove the dye from cheap agricultural diesel.
The 'washed' diesel would be loaded into another tanker and moved around the country where it would be sold as more expensive road diesel.
However, because of the acid used in removing the dye, the 'road diesel' can often cause serious damage to engines.
Customs officers believe the factory raided today had a conservative capacity to launder 7.5m litres of fuel a year, which would result in a loss to the Exchequer of around €4.5m.
A total of 25,000 litres of diesel was also recovered while 19,000 litres of highly toxic wash, the by-product of the laundering, was also found on the site.
One man is due before the District Court next month in relation to today's discovery.
