Following a hack on HSBC Turkey which exposed the details of 2.7 million customer credit card accounts, the bank has said it will not be reissuing cards to those affected because it claims the cards are still secure.

The data breach, which occurred last week but only made public yesterday, has hot be linked to any fraudulent transactions as of yet.

In an FAQ PDF released by HSBC, the bank said: "Information compromised consisted of card and linked account numbers, card expiry dates and card holder names of our customers. There is no evidence that any of our customers’ financial information or personal information was compromised.

"Our cards are secure and customers can continue to use their cards as usual."

Trey Ford, who is a security strategist for Rapid7, said: A couple of things stand out – the attack happened last week, and they’ve caught it already, and they caught it themselves. This is impressive given that the vast majority of breaches are detected by third parties, and often not for months."

"We would like to inform you that HSBC recently identified and stopped a cyber-attack on our credit card and debit card systems in Turkey," HSBC said in its initial statement.

"On identifying the incident, we took immediate action to safeguard our customers. We have launched an ongoing investigation in cooperation with the Banking Regulation and Supervision Agency of Turkey and other relevant authorities."

Ford also sheds some light on why HSBC have taken the decision not to reissue the affected credit cards.

He said: "HSBC is underscoring that cards will not be re-issued at this time, and that the compromised data will not impact Internet Banking, ATM transactions, and telephone banking services; customers can continue using their cards with confidence. This is because "card present" transactions require additional information that would be encoded on the magnetic strip, and for "card not present" transactions, the card security code (CVC or CVV2) would be required to transact business."