Marks and Spencer has confirmed that a laptop containing information on 26,000 employees was stolen three weeks ago.

The laptop was taken from a printing firm that had been given the personal information in order to write to employees about pension changes.

'It was a big smash and grab job. They took a large number of items and weren't specific after employee details,' said a spokesperson.

The laptop contained salary details, addresses, dates of birth, national insurance and phone numbers, but was password protected.

Two days after the theft, M&S wrote to all staff whose names were on the laptop, warning them of the risk and offering free credit checks as a result.

At first the firm revealed the exact nature of the personal details on the stolen laptop only at internal meetings or if staff made further enquiries to a helpline.

Last week the NHS admitted a laptop containing the names, addresses and bank details of some 10,000 employees has been stolen from a building in Truro, Cornwall.