The Data Protection Commissioner is investigating a compromise in the details of nearly 70,000 credit card holders.
More than 60,000 Supervalu Getaway Loyalty programme members, 8,000 Axa loyalty customers as well as a number of Stena line customers have had their credit card details compromised.
The breach, which has affected companies who use the Loyalty Build System, was identified earlier this month but is now understood to be worse than initially thought.
Update at 14.00pm
It is now known that the C-V-V number at the back of the card was also accessed.
AUDIO: Data Commissioner Billy Hawkes has this advice: