SEX offenders are facing lie detector tests to make sure they are not reoffending.

Essex Police has trained an extra officer to carry out the polygraph tests and now boasts more trained officers - at four - than any other force.

A spokesman for Essex Police said: “Our teams really feel like we are ahead of the curve on this one. We were an early adopter of the technique and we’ve invested in officers to ensure that we’re carrying out these tests to the highest standard we can.”

The news was revealed in a performance report by Asst Chief Con Andy Prophet, who heralded the latest appointment as one of the force’s key achievements in managing sex offenders.

Essex Police now has four polygraph officers working across the county and was one of the first in the country to train officers in this discipline in 2016.

Three officers work with the Management of Sexual Offenders and Violent Offenders (MOSOVO) team interviewing registered sex offenders.

The fourth officer works on the Police Online Investigation Team (POLIT) where they will test people who are on bail for grooming offences or for having indecent images of children in a bid to determine whether any further offences have been committed.

Polygraph tests are not mandatory, meaning most registered sex offenders (RSOs) must volunteer for interview.

However now the tests for some are being included in the register agreement and so they must comply if requested to do so.

The tests focus whether offenders are complying with the terms of orders from the court which can include complete internet bans or bans from deleting search histories.