An estimated €1.2m in cash has been seized by gardaí after a series of searches in Wexford and Dublin today.
Gardaí attached to the National Drugs and Organised Crime Bureau stopped two vehicles off the Clonard Road in Wexford town at around 10.45am and a large quantity of cash was seized.
Three men - aged 47, 38 and 29 - were arrested on suspicion of money laundering.
Further searches were conducted by gardaí in Wexford this evening and a further amount of cash was seized.
A fourth man, aged 44, was arrested on suspicion of money laundering offences.
All four men are being held at Wexford Garda Station.
As part of the same operation a significant quantity of cash was seized during searches in Dublin this afternoon.
Assistant Commissioner John O'Driscoll, who is head of Special Crime Operations (SCO), said: "Depriving organised crime groups of the proceedings of their criminal activity is a particular priority for the Garda Síochána.
"For this purpose, today, the Garda National Drugs & Organised Crime Bureau (GNDOCB) is undertaking searches in Dublin and Wexford, which has resulted in the arrest of three suspects and the seizure of a very significant quantity of cash."