Gardaí (Irish police) have arrested three men as part of an international investigation into an organised crime group from Romania.
They also seized documents relating to suspected fraud in Northern Ireland.
Three Romanian men - aged 24, 25 and 31 - were arrested at a house in Letterkenny, County Donegal.
The PSNI and the European Union's law enforcement agency, Europol, were involved in the investigation.
In the raid on Tuesday morning, police seized a large amount of fraud paraphernalia including suspected cloned credit cards, bank account details, false Romanian identity documents, credit card machines, and suspected stolen Irish and UK passports.
Stolen driving licences were also seized, along with two cars bought on finance obtained on bank accounts opened in false names.