CONFIDENTIAL details of dozens of bank customers were found dumped in a back street in Bolton town centre.

The files — which contain names with bank card numbers, including expiry dates, security codes, account numbers and signatures — were found in an Asda carrier bag behind the Abbey branch in Deansgate, Bolton.

The papers also detailed customers’ mortgage payments, home values, loans, jobs and salaries, as well as household budgets, including estimates of monthly bill payments.

Most of the papers were photocopies or computer printouts headed with the red Abbey logo, and they contained details of mortgages ranging from £50,000 to more than £110,000.

The discovery was made by Terence Howarth, aged 20, as he was walking his girlfriend’s dog in the town centre.

Mr Howarth said he was walking along Hotel Street at about 11.30pm on Sunday when the dog, Bertha, ran down Back Hotel Street, the alleyway where a number of businesses, including Abbey, leave bins.

He said that as he went to retrieve the seven-year-old Boxer, it started rooting around and he noticed an Asda carrier bag next to one of the bins.

Mr Howarth could not believe his eyes when he looked in the bag and found a three-inch thick wad of papers full of highly personal information.

He said there were other papers with more personal details scattered in the alleyway.

Mr Howarth said: “I’m just shocked. Those papers should have been shredded."

Anthony Frost, head of corporate communications for Abbey, said the bank had taken steps to ensure the blunder did not happen again.

He said: “We apologise for what has happened and take this matter very seriously."