Gardai seized more than €2m in counterfeit notes during an investigation into the activities of dissident republicans.
The notes are of €50 denominations and are believed to be of high quality.
Gardai have described the counterfeiting operation as ‘‘highly sophisticated.’’
Three men have been charged and brought before the courts and the Garda investigation is continuing.
A specialised Heidelberg industrial printing press was also seized.
Gardai have warned businesses and members of the public to exercise caution when handling €50 notes.
They believe the counterfeit notes are already in circulation.