HSBC's has launched a review of its customer security setup to address the flaws uncovered by researchers from Cardiff University, which could affect three million UK customers. The problem allowed security researchers armed with key logging software to access customers' bank accounts after only nine attempts.

However, experts disagree about the severity of the loophole, and point to more positive moves in the sector. Andrew Moloney, senior product manager at RSA Security, said: "No single technology can stop fraud - you need a layered approach to security, and it's not simply a case of getting a bigger lock on the door. That said, it's essential that UK customer confidence is maintained."