Three laptop computers containing the payroll details for the Metropolitan Police Service have been stolen.
The computers were taken in a raid last Thursday from the London offices of LogicaCMG - responsible for the Metropolitan Police's pay and pensions services - but was only discovered when staff arrived for work the following day.
The Metropolitan Police said in a statement: "We believe the risk of staff members falling victim to either fraudulent activity or identity theft is minimal.
"However, we are in discussion with CIFAS (the UK fraud prevention service), APACS (UK payments trade association) and credit reference agencies about what action we can take to further safeguard our staff from becoming victims of fraud."
It also said that it was in the process of informing workers of the incident and has conducted a risk assessment of the data on the laptops.
Burglary Squad officers are investigating the raid, supported by the Specialist Crime Directorate.
According to Gary Clark, EMEA VP of security technology firm SafeNet, businesses need to take action to protect their data without the introduction of a UK law, similar to the California Security Breach Information Act, which requires organisations to inform individuals if the security of private information has been compromised.
He said: "Storing data unencrypted on mobile devices is courting trouble, as the theft and loss of laptops, mobile phones and other devices will inevitably occur. The data stored on them is then at risk of being accessed by these criminals and this can harm both the individual as well as the organisation."
Clark added: "Information is the key to business success, and thus all data, whether at rest in databases or on the move across networks and on mobile devices, should be protected.
"Businesses should be hearing enough horror stories in the press to be implementing better security, without legal requirements having to be enforced. Ultimately, the organisation loses out if data is accessed by criminals and thus it is in their own best interests to protect all confidential data placed in their care."
One man was arrested on suspicion of burglary last Friday and taken to a south London police station for questioning. He was later bailed to return to the station at a later date, pending further enquiries.