The operation involved searches on three private residences in the Garda Southern Region and Eastern Region.
The searches were led by the Special Detective Unit (SDU), supported by the Garda National Immigration Bureau (GNIB) and local Garda resources.
The investigation is part of and being supported by International Law Enforcement and Europol.
In excess of €100,000 cash in various currencies has been seized, along with electronic devices and documentation.
The GNIB is investigating the residency status of those involved, who are non-Irish nationals.
A spokesperson for An Garda Síochana said this is “an evidence gathering phase of the investigation.”
No arrests were made in yesterday’s operation.
AGS said that investigations are ongoing.