Gardai have issued a warning to the public to be cautious about the use of credit cards, emphasising that people should not let their cards out of their sight while carrying out transactions.
The warning follows the discovery of miniature "swipe card" equipment which can be used to copy secretly information from credit cards.
Battery-powered swipe card devices have been used to copy information from people's credit cards in the State.
The information from the magnetic strip on the credit card is then transferred to a computer, replicated and transferred to a fake card.
Gardai have found equipment used to emboss numbers with foil tipping on to the illegally manufacture cards.
Some 380 stolen or manufactured cards have been discovered along with the computer, embossing and tipping machinery.
Credit cards seized by gardai in Dublin have affected such companies as the Royal Bank of Scotland, AIB, MBNA, Barclays Bank, Midland Bank, National Westminster Bank, Lloyds and financial institutions such as American Express, Master Card, MBNA, Smith Barry, Halifax, Merrill Lynch and Abbey National.
Gardai warned that the public should be vigilant as there could find themselves victims of a credit card fraud.
A senior officer said: "We would warn people to be careful about how they handle their credit cards.
"Watch while your card is being swiped - anywhere, including restaurants. Always get a receipt. Check your account regularly.
"As soon as a card is missing report it to your bank. If a card is lost and it has been used illegally there can be a question of liability if it has not been reported stolen.
"We know that cards are being swiped under counters. This can happen anywhere from petrol stations to shops to restaurants. The public needs to be vigilant to this sort of crime."
This is the first time that a manufacturing facility for illegal cards has been discovered in the State.
The equipment was found in Dublin on Wednesday after an investigation by the Garda Bureau of Fraud Investigation. Previously the Republic has been targeted by international credit card fraudsters from west Africa, particularly the 419 Coalition from Nigeria which has been involved in fraud in the US and Europe on a vast scale.
US authorities estimated that the 419 Coalition, named after the Nigerian Criminal Code section on fraud, was responsible for $5 billion worth of credit card fraud up to 1999.
This group is not thought to be linked to the find of the manufacturing facility.