Police are using lie detector tests to target suspected and convicted sex offenders across York and North Yorkshire.

Detective Superintendent Heather Whorriskey, North Yorkshire Police’s head of safeguarding, revealed officers have used a polygraph test 87 times since it first started using the equipment in October 2020.

The tests work by measuring how a person responds to certain questions, such as if their blood pressure rises or if they get sweaty palms, to detect traits associated with lying.

However, the tests are controversial as they are not 100 per cent accurate and the results can’t be used as evidence in the courts.

After a guest on ITV’s Jeremy Kyle Show died after reportedly failing a lie detector test, MPs in 2019 criticised the show's producers. The team behind the show had admitted they did not know how reliable their lie detector tests were.

Det Supt Whorriskey, speaking at a public accountability meeting of the North Yorkshire Police, Fire and Crime Commissioner, said the force uses the tests before a suspect is charged to investigate if they have been in communication with children using a device.

The tests are also used on “lower-level” people on the sexual offenders' register to understand the risk they might pose to the public.

However, Det Supt Whorriskey said many people about to take the test reveal things before it starts as they “realise their answers are likely to give away some untruths".

She said: “It’s used quite significantly whenever offenders are using communication devices to assess whether or not they have engaged in further communication with children. We’re able to use that to prioritise those devices for examination within our digital forensic unit.”

Det Supt Whorriskey said the use of polygraph tests is increasing and will be used 13 times in the next three weeks alone. She added: “It identifies unknown risks and offences we would not have known about without having used the equipment. It’s absolutely value for money.”