Barclays' customer details stolen and "sold" for £50 per file to City brokerage

27,000 files of customers to Barclays' financial planning arm stolen and sold to City brokerage

A security breach at banking giant Barclays has exposed the personal files of up to 27,000 customers who had sought financial advice from the bank.

The details included earnings, savings, mortgages, national insurance numbers, marital status, health information and dependents. It also included the results of a questionnaire intended to reveal their attitude to financial risk-taking.

According to the Daily Mail, which exposed the breach, the information could be used to persuade the bank's customers to buy into questionable investments. The exposure was made after a whistleblower approached the newspaper, which claims to have seen a selection of files.

The information was passed on to traders in the City, who used the information in an attempt to push investments on the "victims".

"They would start by saying that they had a great investment opportunity that would suit someone on a particular income or with a particular amount of money to invest," the source told the Daily Mail. "Of course, they already knew this about the person they were talking to."

According to the report, the whistleblower became aware of the scandal after the head of a brokerage firm sought to sell them on as "secondary data" - after rinsing the leads of every penny his firm could get out of them.

"Between December 2012 and September 2013 the firm persuaded victims to buy rare earth metals that did not exist, it is claimed. The whistleblower estimates up to 1,000 people could have been ‘scammed'. When the investors began to suspect they were being fleeced he said the boss chose to ‘shut the trading floor'," claims the Daily Mail.

Furthermore, when investors began to suspect that they were being fleeced, the brokerage firm boss ordered the destruction of all the evidence - including his laptop and paperwork - as well as the wiping of all computers.

A spokesperson for the Information Commissioner's Office (ICO) confirmed to Computing that it is investigating the matter.

In a statement, the ICO said: "It's crucial that people's personal information is properly looked after. We'll be working with the Mail on Sunday this week to get further details of what has happened here, as well as working with the police."