Rogue hauliers have been warned by the Revenue Commissioners that they are to step up their campaign to detect illegal usage of motor fuel.
The move has been welcomed by the Irish Road Haulage Association, which wants the rogue operators put out of business.
Already this year, marked mineral oil has been discovered in 471 fuel tanks.
There have also been seizures of laundered fuel, green diesel and Northern Ireland kerosene totalling over 57,000 litres.
