Bank account details, telephone numbers, addresses and a host of other sensitive customer information has been found in rubbish bags behind a High Street bank.

The two black bags contained banking details for the company in charge of Brighton Festival's Udderbelly venue.

Halifax customer Richard Inverarity, 53, of Brunswick Road, Hove, made the discovery after watching a television programme about ID fraud.

He said: "I thought I would go and have a look behind Halifax and I found these two bags with bank account numbers and telephone numbers in. There was a lot of rubbish as well, mostly food, but these documents should have been shredded."

An FSA spokeswoman said: "We require firms to have in place adequate systems to prevent people getting consumers' confidential details. In the past we have taken this very seriously."

The watchdog fined building society Nationwide almost £1 million in February this year after a laptop was stolen from an employee's home.

Nationwide did not start an investigation until three weeks after it was taken. It claimed the information on the computer could not be used by ID fraudsters but that did not stop the FSA handing out a £980,000 fine.

The Argus called several customers whose details were found at the branch behind Udderbelly.

Richard Creek, of Brighton, said: "It is disgusting and there is no excuse for it. You put your trust in them to keep your details secure and they do this."

Another, who did not wish to be named, said: "It's dreadful.

I'll be taking this up with the Halifax immediately."

Penny Sims, spokeswoman for the Udderbelly, said: "If there has been a breach of security we are very unhappy about it and will be taking it up with the bank as soon as possible to find out more on the situation."

A Halifax spokesman said he could not comment on the incident but the bank would launch an investigation.

He said the bank normally shredded documents and had lockable waste bins.

Last month, The Argus highlighted identity theft hotspots in Sussex. About 35 per cent of central Brighton's population fall into a high-risk category.

Other ID theft hotspots were Horsham, Haywards Heath, Worthing and Chichester.