Gardaí have confirmed a 39-year-old woman has also been arrested in connection with the Wexford seizure.
Earlier, one of the four men being questioned was released after a significant sum of cash was seized in Dublin and Wexford.
The discovery in Dublin was made during searches by Garda in the Ballyfermot area
The seizures are believed to be linked to the Kinahan cartel.
The men aged 29, 38, 44 and 47 - were arrested yesterday morning.
At 9:45am yesterday morning, Gardai investigating organised crime stopped two cars near Clonard Road in Wexford.
They arrested three men aged 29, 38 and 47 on suspicion of money laundering.
Image: Garda Press Office
Assistant Commissioner of Special Crime Operations, John O'Driscoll, says the amount of cash seized is significant.
"I can't say precisely what's involved and the reason for that is that the money is packed in such a way that it will take some time to count it because we have to preserve evidence in the process but it is in hundreds of thousands."