Insurance giant Zurich has lost the sensitive personal account details of 641,000 customers held on backup tape.
The company admitted the tape had been missing for over a year in South Africa, after it was lost en route to a secure storage unit in August 2008. But it has only just noticed the loss, and launched an investigation.
Zurich confirmed to Computerworld UK that the tape contained the details of 51,000 UK customers. Its entire South African customer base of 550,000 clients was also lost, alongside the details of 40,000 customers in Botswana.
In some cases the losses involved names and contact details, as well as bank details for customer payments.
Zurich has apologised to customers, as well as informing the Financial Services Authority. It hired accountants KPMG to investigate the loss.
Annette Court, chief executive of general insurance for Europe and Zurich Financial Services, said the loss was "unacceptable" and that the company takes security "very seriously".
"We are putting a great deal of investment into strengthening our internal processes to ensure that incidents of this nature do not happen again in the future," she said.
The company insisted there was "no evidence" that any details had been compromised.