LIE detector technology is being used to root out potential benefit cheats.

People who phone to claim housing and council tax benefits will have their voices monitored by high tech telephone software which detects subtle voice changes that indicate if they are giving false details.

Callers will initially be asked basic questions - their name, address or date of birth - so that the software becomes used to the pitch and tone of their voice.

It then can detect changes in a caller's voice caused by increased levels of stress. Hesitation and repetition have been identified as a sign that people are not telling the truth and will cause a 'high risk' display to flash up on a screen in front of the staff member.

They may then be subject to further investigation, such as a home visit.

Otherwise the caller is branded 'low risk' - resulting in a claim being fast-tracked to avoid the need for physical evidence of income or family status

The scheme is being piloted over twelve months in Bury and 18 other council areas across the country and is funded by the Department for Work and Pensions. If it is successful it could be adopted across Greater Manchester.

People will be warned at the start of the call that they are being monitored by the Voice Risk Analysis (VRA) system.

Suspicious

Staff have also been trained to spot the 'telltale' signs of callers not telling the truth and benefit bosses stress that the ultimate decision rests with the advisor - not a machine. They say the system is being used to flag up suspicious calls so they can be acted on and will speed up the process for the majority of claimants by reducing the onus on providing documentary proof of their circumstances.

Coun Peter Redstone, Bury's executive member for resource, said: "People have told us that benefit fraud is a big concern and hopefully this new system will help identify cases of higher risk so they can be looked at in more detail."

The system is already widely used in the insurance sector. The technology was first tested by a council in north London last year then six more

Benefits fraud is estimated to run to a total of £0.8bn in 2006/7, according to the DWP said. Latest figures show there were more than 52,000 prosecutions in 2005/6.

A council spokesman added: "Results from the initial pilot found the technology to be of great benefit both financially to local authorities and also to improve the customer experience of the benefits service. The new technology will help identify those customers seen as a lower risk who will then benefit from a reduced level of checks. The system will flag up higher risk cases and this will enable staff from the benefits service to have a more detailed look at these cases before making a decision.

"Machines are not making decisions. It will always be the staff and obviously cases vary."

Coun Redstone added: "The great thing about this technology is that it does not take the decision away from the member of staff as they still have the final say over the decision.

"As the majority of cases are of low risk this new system will help improve efficiency and ensure high customer service."