UK mobile phone chain Carphone Warehouse says it has suffered a serious data breach that may have seen the banking details of 2.4 million customers stolen by hackers.
The breach was discovered on 5 August at a division of Carphone Warehouse that operates websites for OneStopPhoneShop.com, e2save.com and Mobiles.co.uk and provides a number of services to iD Mobile, TalkTalk Mobile, Talk Mobile, and to certain customers of Carphone Warehouse.
The company began alerting customers of the breach - which saw names, addresses, date of birth information and bank details lifted from its servers - by e-mail over the weekend.
Around 480,000 of the 2.4 million customers affected by the breach are TalkTalk Mobile customers.
Up to 90,000 customers may also have had their encrypted credit card details accessed, the company says in a statement.
Parent company Dixons Carphone says it has secured its systems and hired a cybersecurity firm to investigate the breach and determine exactly what data was affected.
"Currys and PCWorld and the vast majority of Carphone Warehouse customer data is held on separate systems and has not been accessed during this incident," says the company.