Britons are concerned about the trend for banks to have call centres abroad - but most do not know if their own bank has operations overseas, research has shown.

Two-thirds said they would be very concerned if they knew their personal banking details were held in a customer service centre outside the UK and 28 per cent would be slightly concerned.

Around 83 per cent also said they would change banks if they thought their account details had been compromised, or other customers had lost money as a result of fraud at one of the centres, according to audit firm KPMG. But despite their concerns, more than three-quarters admitted they had no idea whether their bank had operations overseas.

Karen Briggs, head of regulatory services at KPMG Forensic, said: "Many UK customers seem confused in their attitude towards the offshoring of banking.

"There are clear concerns around the concept of overseas call and data centres, and their perceived vulnerability to data breaches - and there have already been widely-publicised instances of the selling-on of customer data.