Gardai in Co Monaghan have arrested one man following a raid on a diesel-laundering plant in Co Monaghan yesterday morning.
They have not ruled out subversive involvement in the operation. The plant was in a large shed on a farm at Oram, near Castleblayney, and contained machinery worth hundreds of thousands of pounds.
It is similar to plants raided near the Border in the last year. In the plants coloured diesel is chemically treated, or laundered, and sold on as clear diesel at a substantial profit.
Coloured diesel is for agricultural use and sells for about one-third the price for which the laundered diesel is sold. The laundered product is sold through a network of garages around the country to unsuspecting motorists.
Gardai and customs officers say the laundered diesel may contain traces of the acids and chemicals used to remove the colour, or "marker", and can damage car engines.
Yesterday's raid involved gardai from Castleblayney and Carrickmacross and followed weeks of surveillance on the farm. A man in his 30s was arrested at the scene under the Criminal Justice Act.
Customs officers began dismantling the operation yesterday afternoon. When gardai raided the plant, there were three tankers of coloured diesel and one of washed diesel on the premises. They estimated that about 36,000 litres of washed diesel was recovered.
Insp Noel Cunningham, who oversaw the Garda operation, said: "This is a significant seizure, which has put out of operation a plant that we believe has been only recently set up. We have called in customs officials to dismantle it. Although there is no evidence at the moment, a subversive or criminal element cannot be ruled out."
He said gardai were concerned for motorists who were sold the laundered diesel because they were unaware there could be acids in it.
The trade in laundered diesel has been associated with the Border area and the exchange rate between the Irish pound and sterling dictates which side of the Border the washed diesel is bought and sold.
Garda sources believe members of the IRA have made large profits from both the laundering of diesel and the smuggling of tankers of the cleaned fuel across the Border.
Yesterday's seizure is the latest in a series of large-scale diesel-laundering operations to be raided and dismantled in the last 18 months. Despite their success, gardai and customs are aware that no sooner has one been put out of action than another is set up to replace it.