Online auction site eBay has become an unwitting data mule, when it allowed a computer to be sold through its site that contained customer information from the Royal Bank of Scotland.

The computer hard drive was sold for a paltry £35 but the information on it was priceless, as it contained highly sensitive documentation on American Express, NatWest and Royal Bank of Scotland customers.

The information included personal home phone numbers, account numbers, addresses, sort codes and even customers' signatures.

This loss of information is said to be one of the worst ever reported in the UK and comes after a spate of government data loss reports.

Investigations are still ongoing

The information was meant to be stored by Graphic Data, a subsidiary of Sala International. In a statement to the press, the company insists that the data was not meant to end up on eBay:

"The IT equipment that appeared on eBay was not planned to be disposed [of] by the company and investigations are still ongoing to find out how this equipment was removed from one of Graphic Data's secure locations.

"We take customer privacy and data security very seriously. This incident is extremely regrettable and we're taking every possible step to retrieve the data and ensure this is an isolated incident."

Not the first time

The loss of data does mean that everybody whose data was included on the hard drive may have to change their credit card and bank account details.

This is not the first time NatWest has been involved in a data scandal. The company was fined £980,000 by the Financial Services Authority just last year after losing a laptop full of customers' information.