The company at the heart of the data breach involving Supervalu and Axa Insurance customers says it has been the victim of a "sophisticated criminal attack".
The credit card details of up to half a million people across Europe have been compromised by the data breach at Ennis-based firm Loyaltybuild.
Credit card details in Ireland belonging to more than 62,500 Supervalu customers, 8,000 Axa customers and a number of Stena Line customers have been compromised.
Loyaltybuild, which operates part of Supervalu's Getaway Breaks scheme, says it has notified the Gardaí of the breach.
A garda spokesperson says no investigation has yet been launched.
The breach was identified earlier this month, but is now understood to be worse than initially thought.
Data Protection Commissioner Billy Hawkes said up to half a million customers across Europe have had their details compromised.