The middle-aged mentor has been the subject of a lengthy CAB investigation and is on the run after failing to show up at his trial late last year.
The CAB was previously involved in a drive against 'Mr Big' when it targeted houses and a cafe in the north Dublin area which were linked to the feared crime boss whose crew are suspected of more than seven gang murders.
The bureau recently seized a high-powered vehicle from 'Mr Big' and is now in the process of targeting other assets linked to him.
However, sources say that it may well be a "difficult task" because he is "very cash savvy".
A source explained: "The criminal fraternity recognise how good this individual is with money and evidence of this was seen when a junior member of his gang was awarded a five-figure sum in a compensation claim.
"The fella -- who is a prolific street dealer in the Darndale area -- gave all the money to 'Mr Big' to invest for him.
"Mr Big has led his crew in a very organised and almost discreet fashion for a number of years and they even have a fleet of 'company cars' if you like.
"But the vast majority of these vehicles are not flashy -- you are talking about space wagons or Fiat Puntos or cars like that.
"It will now be up to the Criminal Assets Bureau to tangle through all the cash, cars and houses if they are to be successful."
The Herald has learned that a brother of the drug dealer who handed over his major compensation claim to 'Mr Big' was the criminal who was stopped in a car with the gang boss in the Marrowbone Lane area of Dublin's south inner city last month.
Gardai discovered cable ties and balaclavas in the car but 'Mr Big' and his close associate who lives in the East Wall area were not charged with any criminal offence.
It is believed that Mr Big's associate -- who originally comes from Coolock -- is also being targeted by the CAB over a five-figure tax debt.
Since his return to Ireland in December, sources say that 'Mr Big' has been spending his time between Dublin -- where he has been staying in hotels and safe houses, and Northern Ireland -- where some of his closest and most ruthless associates are now based.
Alan Ryan's Real IRA faction who Mr Big's crew have been involved in a bitter feud with for over a year have been wracked by in-fighting and highly successful garda operations since Ryan's murder.
But sources say they are still "gunning for revenge" over the murder of Ryan.