"So much has been said already about the availability of information disposal tools, increasing legislative pressures and the growing literacy of computer users that it is difficult to explain why there is still such poor cleansing of disks," Jones said.

He said business must adopt and enforce a universal information disposal policy for the sale of disks.

"When organizations dispose of surplus and obsolete computers and hard drives they must ensure that, whether they are handled by internal resources or through a third-party contractor, adequate procedures are in place to destroy any data and also to check that the procedures that are in place are effective," he said.

Information contained on the drives included payroll information, mobile telephone numbers, copies of invoices, employee names and photos, IP addresses, network information, illicit audio and video files, and financial details including bank and credit card accounts.