A businessman who is regarded as a kingpin in the cross-border fuel laundering and cigarette smuggling trade will be served with a seven-figure tax demand early this year.
The bill is being drawn up by the Republic's Criminal Assets Bureau (CAB) following a multi-agency investigation into the man's activities.
The major player in the black economy is alleged to be at the top of a criminal pyramid with links to republican groups.
At one stage, he fell foul of some of his republican accomplices and was given a bad beating and told he would not survive if he crossed them again.
Last September he was one of four men detained following a joint swoop by the Garda and the Irish revenue's Customs Service, backed up by CAB.
They were arrested by armed detectives after officers intercepted a truck taking a payment of nine million cigarettes from Dublin Port towards the border.
Detectives stopped the truck on the M1 motorway, near Castlebellingham, Co Louth, and seized the cigarettes, which had a retail value of €4.3m (£3.5m).
Cab is now putting the final touches to the tax bill to be served on the man, who has been a key target of the gardai and customs for several years.
Last year, CAB officers carried out a total of 25 fuel laundering and cigarette smuggling searches in the border counties targeting 21 figures and confiscating assets amounting to €1.7m (£1.4m).
Among the suspects are former senior members of the Provisional IRA hierarchy in south Armagh.
In a separate operation, the bureau also dealt a financial body blow to a Cork-based gang of cigarette smugglers with strong connections to Poland.
As a result of their activities, CAB has handed €10m (£8.3m) to the Irish exchequer over the past year, comprised of about €5m (£4.1m) seized under the Proceeds of Crime Act, €5.3m (£4.4m) in taxes and close to €500,000 (£415,000) in social welfare overpayments. The total is well up on last year.
Although €5.3m (£4.4m) has been paid to settle tax bills, the bureau made tax demands over the year for €12.9m (£10.7m) but a lot of the court applications have yet to be determined.
The Criminal Assets Bureau was set up in the Irish Republic in 1996 in the wake of the murders of Sunday Independent journalist Veronica Guerin and Detective Garda Jerry McCabe, who was shot dead by the Provisional IRA in Adare, Co Limerick. It has powers to seize the illegally acquired assets of criminals involved in serious crime.