Investigations have been launched after a report that thousands of confidential files with Barclays Bank customers details had been stolen and sold. The Mail on Sunday said an anonymous whistleblower had handed it a memory stick with the personal data of 2,000 Barclays customers, saying information on a further 25,000 was also available.
The files are said to hold passport and national insurance numbers, as well as money and health information.
The report said the data, which also contained the individuals' attitude to risk, had been sold to "rogue City traders" and was "worth millions on the black market because it allowed unsuspecting individuals to be targeted in investment scams".
Barclays said it was investigating.