Barclays is investigating after thousands of customer files who sought advice from the bank were reportedly stolen and sold on to rogue City traders.
The Mail on Sunday reports customers from its financial planning arm had details of their earnings, savings, mortgages, health issues and insurance policies passed on to brokers.
The information came from a whistleblower who passed the newspaper 2,000 customers’ details but claimed it was from a batch of up to 27,000.
He said the files are for sale at £50 per customer and estimates up to 1,000 people could have been scammed.
All customers involved are believed to have sought financial advice from the bank and passed on their details during meetings with an adviser.
The so-called ‘Barclays leads’ were passed on between December 2012 and September last year.
A Barclays spokeswoman told the newspaper: “We are grateful to the Mail on Sunday for bringing this to our attention and we contacted the Information Commissioner and other regulators on Friday as soon as we were made aware.
“Our initial investigations suggest this is isolated to customers linked to our Barclays Financial Planning business which we ceased operating as a service in 2011.
“We will take all necessary steps to contact and advise those customers as soon as possible so that they can also ensure the safety of their personal data.
“Protecting our customers’ data is a top priority and we take this issue extremely seriously. This appears to be criminal action and we will co-operate with the authorities on pursuing the perpetrator.
“We would like to reassure all of our customers that we have taken every practical measure to ensure that personal and financial details remain as safe and secure as possible.”
A spokesman for the Information Commissioner’s Office said: “It is crucial that people’s personal information is properly looked after. We will 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.”