By Chris A'Court
BBC Radio 4's Money Box
Staff at Marks and Spencer have been warned they may be at risk of identity crime after the theft of a laptop.
M&S believes no-one has yet become a victim of identity crime
Salary details, addresses, dates of birth, national insurance and phone numbers were on the machine which was stolen from a printing firm.
M&S has told BBC Radio 4's Money Box that 26,000 present employees in its final salary pension scheme are at risk if the data is accessed by criminals.
It is offering free credit checks to the people affected.
The laptop was stolen in a burglary on 18 April from a printing firm that had been given the personal information so that it could write to M&S employees about pension changes.
It is believed it was an opportunist theft rather than a planned burglary, and that the laptop was taken for its own value rather than the data on it.
Two days later M&S wrote to all the staff whose names and details were on the laptop, warning them they were at risk and reassuring them that their account and card details had not been compromised.
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.
The firm told Money Box it felt this was a responsible way to deal with the matter, and that the laptop was also password protected.
M&S believes no-one has yet become a victim of identity crime as a direct result of the security breach, but the laptop has still not been recovered.
Ed Mayo, chief executive of the National Consumer Council (NCC) has expressed concern over the security breach.
He told Money Box it illustrates how not enough is being done to keep personal information safe.
"Here we've got Marks and Spencers - which is a relatively trusted brand - losing data for their own staff, therefore every company in Britain is, surely, vulnerable to this," he said.
"Every company really now should take action to ensure they've got the systems and processes in place to minimise this risk."
He said the NCC planned to campaign for legislation at UK or EU level for companies to take faster action on this issue.
BBC Radio 4's Money Box was broadcast on Saturday, 5 May 2007 at 1204 BST.
The programme was repeated on Sunday, 6 May 2007 at 2102 BST.