The credit card details of up to half a million people across Europe have been put at risk.
Customers who signed up to loyalty schemes at a number of Irish companies are affected.
The card details of well over 70-thousand Irish customers have fallen victim to a cyber-attack, and now as many has those of half a million Europeans could be in criminal hands
This all started last week when SuperValu contacted customers of its loyalty programme GetAway Breaks, which is operated by LoyaltyBuild.
The County Clare firm's admitted the level of risk is much higher than they'd thought, and that thousands of AXA and Stena Line loyalty customers are also affected.
Data Protection Commissioner Billy Hawkes is investigating.
Customers are also warned to be careful of any unsolicited communication from the Loyalty Breaks schemes, in case its hackers trying to get more information.
