CUSTOMS officers on both sides of the Border are to introduce a new fuel marker to boost the campaign to tackle the multi-million euro laundering racket.
The marker will be launched simultaneously North and South and will make it more difficult for the gangs to remove the dye as it is highly resistant to known laundering techniques.
Launderers primarily target green diesel in the Republic and red diesel in the North, filtering it through chemicals or acids to remove the government marker.
Marked agricultural fuel qualifies for lower tax, which means it is sold at lower prices than road fuel.
If the dye is removed, criminals can sell it on at a huge profit. Officers at the forefront of the fight against the launderers have been pressing for a new marker scheme for some time.
Today tax authorities on both sides of the Border will announce the new move, following consultation with the oil industry.
Crime gangs and dissident republicans have been making huge profits from the racket, mainly in the Border region.
But the intensive garda probing, in counties Louth and Monaghan in particular, as well as PSNI actions in south Armagh and Down, in the wake of the murder of Det Garda Adrian Donohoe more than a year ago, have had a spin-off impact on cross-border crime.
Gardai have established links between certain families known to have been involved in fuel laundering in the past and suspected members of the criminal gang responsible for the fatal shooting of the detective outside Lordship credit union, at Bellurgan, Co Louth, in January 2013.
Customs officers have been working closely with the gardai and over the past three years their efforts have resulted in the shutting down of 119 filling stations for breaches of licensing conditions and the seizure of more than 2.7 million litres of fuel, while 20 oil laundries have been detected and closed, including nine in 2013.
Those nine laundries had the capacity to produce 62 million litres of laundered fuel, representing a potential loss to the Exchequer of €33m.
The pressure in the Border counties has forced the fuel launderers to locate their diesel plants further south.
Customs officers have also clamped down through strict enforcement of the regulations governing the supply of green diesel – and traders have to report regularly to the Revenue about their fuel movements.
New suppliers are now being sought in the greater Dublin area and in Munster. This is one of the factors in the decision by the fuel gangs to set up alternative laundry plants well away from the Border.
"It makes sense for them to move south," one officer said. "A wider range of laundry plants means that tankers do not have to make long journeys to supply the green diesel and risk arousing suspicions in local communities."