Sex offenders will now take lie detector tests in a pioneering police scheme.

Hertfordshire Constabulary has sent officers on an 11-week course to learn how to administer polygraph tests, commonly known as a lie detector.

The project is the first of its kind in the country, with the tests used – alongside other methods – to judge what risks registered sex offenders pose.

Detective Chief Inspector Stuart Orton, who leads for the force on protecting vulnerable people, has been involved in leading the polygraph testing work for the county’s police.

He said: “The polygraph testing is not about sex offenders confessing their crimes it is about assessing the risk they pose to the community and in some cases themselves.

“It’s a measure used with other investigative tools by specialist officers in our Child On-line Safeguarding Team to protect the public.

“In many instances individuals have been arrested and are on bail waiting for the technical analysis work to be undertaken on their computer equipment.

“By agreeing to an early polygraph test we can work with the offenders and understand the stress they are under and manage them more effectively.”

Hertfordshire police and crime commissioner David Lloyd added: “Managing the risk that sex offenders pose is challenging and the police service must be creative in its approach.

“Hertfordshire Constabulary has been at the forefront of this innovative project which provides specialist officers with further ways to manage risk and I’m confident in the months ahead polygraph testing will prove to be highly successful.”