More than €100,000 has been seized by Gardai investigating serious and organised crime in Dublin.
The money was found after two cars were stopped on the Naas Road yesterday.
Gardai found what they described as a "substantial amount of cash" in the vehicles.
More money was found during follow-up searches.
A man in his 40s, and two women, in their 20s and 30s were arrested on suspicion of involvement in money laundering.
They are being held at Clondalkin, Ballyfermot and Ronanstown Garda stations.