Pensioners have been urged to check their old bank accounts after new research revealed that billions of pounds could be sitting dormant.

The survey from National Savings & Investments (NS&I) shows that more than seven million UK adults believe they have cash sitting in old bank accounts that they have failed to keep track of.

More than a quarter had lost the original account details, while an additional 27 per cent claimed they simply forgot about accounts they opened in the past. 

Age UK claims older people could have lost touch with accounts over their lifetime on a number of different occasions, including when they moved house and changed jobs. 

Michelle Mitchell, Age UK charity director general, said:  "People can lose track of money for many different reasons, including moving house and simply forgetting to update contact details, or losing touch with a pension or account when changing jobs, marrying or divorcing.

"And while many of these accounts hold less than £100, some hold £1,000 or more, which could be a hugely welcome boost to someone's income."