Lie detector tests for freed sex offenders: Regular screening to be introduced to make sure paedophiles are not breaking rules of their release or plotting new crimes Thousands will face regular screening to see if they are plotting crimes Pilot scheme found tests uncovered offenders who still posed a threat It also led to other sex offenders being more honest with probation officers Predatory paedophiles and other sex attackers will be forced to take lie detector tests under changes to the law brought into force today. Thousands will face regular polygraph screening to see if they are breaking the rules of their early release or plotting crimes. If they are found to have lied and breached the terms of their licence they could be taken back to jail to serve the rest of their sentence. Thousands of predatory paedophiles and other sex attackers will face regular polygraph screening to see if they are breaking the rules of their early release or plotting crimes (file picture) A pilot scheme found the tests uncovered offenders who still posed a threat and whose behaviour was getting worse. It also led to other sex offenders being more honest with their probation officers. There are around 3,000 sex offenders on licence in the community at any time, with more than 750 considered to be the most serious cases. Justice minister Jeremy Wright said Britain would have "one of the toughest approaches in the world to managing this group." Officials are expected to focus their efforts initially on several hundred of the worst offenders. Each will be hooked up to the polygraph machine, which measures body indicators such as pulse, blood pressure and breathing rate. A pilot scheme found the tests uncovered offenders who still posed a threat and whose behaviour was getting worse (file picture) After answering a series of control questions, they are then probed on whether they have been reoffending, with the body measurements suggesting whether they are telling the truth. The test in all takes about two hours to complete. The scheme is expected to begin later this year or early next and be spread across England and Wales. During the pilot, sex offenders linked up to the machines made twice as many admissions to breaches of their probation conditions as those who were not put on a lie detector.