Thousands of Lloyds Bank customers have had their data stolen, the bank has confirmed.
The breach, which took place on 30 July, is being investigated by the Police Organised Crime Unit.
Lloyds said a data box was stolen, containing data of thousands of customers with the 'Premier Account'. Information obtained includes names, addresses, account numbers and sort codes.
The bank stressed that the theft only affects customers who took opened the account between 2006 and 2012, and have made a claim on the account's emergency home insurance policy. The device, which has been described as the size of an old camcorder, was kept in a data room owned by Royal Sun Alliance (RSA) insurance, which provided the emergency home cover.
"We recognise this should never have happened and apologise to all customers who have been impacted," said a spokesperson for RSA.
RSA said there was no evidence that anyone's account had been compromised, but customers are being advised to take out identity insurance as an added precaution. RSA also said it would refund customers the £20 for two years' of the insurance.
Anyone concerned can call a freephone number 0800 316 8090.
RSA has issued further advice and information for concerned customers.