Minister for Justice Michael McDowell has said the Irish and British governments are concerned about substantial war chests being in the hands of illegal organisations.
Speaking in London yesterday, the Minister said the battle to prevent paramilitary and subversive organisations from using such assets was ongoing and was succeeding.
The Minister was speaking after it emerged that gardaí had seized files, documentation and computer equipment in a series of raids carried out last week as part of a major investigation into properties allegedly owned by the Provisional IRA.
Gardaí said yesterday that the material seized as part of the raids was being examined by technical experts.
More than 100 detectives took part in the raids last week on around 20 properties in Dublin, Meath, Wicklow and Louth.
As part of the operation, which was led by the Criminal Assets Bureau, a number of premises including a pub, a hotel, homes of company directors and the offices of solicitors and accountants were searched.
The material seized in the raids is being examined to determine whether the pub and the hotel had been bought using the proceeds of crime and used by the IRA to launder money.
Among the properties under investigation are a hotel in the centre of Dublin and a pub in the city.
A man in his fifties from Northern Ireland is at the centre of the Garda investigation.
Gardaí believe he made a substantial amount of money from a fraud operation carried out in the UK in the 1980s.
The man, who had been questioned in Northern Ireland about the murder of a member of the security forces, had an exclusion order served against him from Britain in the 1980s.
Gardaí believe that when he returned to Ireland he invested money in a pub in Dublin.
The man concerned subsequently invested in the hotel in the city centre. He also has a substantial portfolio of property in Dublin and elsewhere.
A Garda spokesman said yesterday that the search phase of the operation had concluded for the present.
Forensic experts are examining files, computers, laptops and disks seized as part of the raids.
The raids were carried out based on information generated as part of the cross-Border investigation into the €36 million Northern Bank robbery in Belfast in December 2004.
Mr McDowell said that it was entirely co-incidental that details of last week's Garda raids emerged just hours before the publication of the report of the Independent Monitoring Commission on paramilitary activity.
He said the two issues were not connected and that the Criminal Assets Bureau and the Assets Recovery Agency in Northern Ireland regarded all proceeds of crime "as their legitimate quarry".