A lie detector test will be used by a council to see if benefits claimants are telling the truth.
The method called ‘voice risk analysis’ has been introduced to check details that people have provided about their claims.
It is used by contractor Capita during telephone interviews and will cost about £50,000.
But numerous academic studies have cast doubt on the accuracy of lie detectors with some claiming they are little better than chance.
Cornwall council has admitted that a senior councillor has resigned over its use of the system to combat fraud.