PAEDOPHILES and rapists in Staffordshire are having to take lie-detector tests in a bid to stop them re-offending.

They must take regular tests as a condition of their release from prison and could be sent back to custody if they refuse as a breach of parole.

Staffordshire Probation Service is one of nine areas taking part in a new three-year trial of polygraph sessions on sex offenders.

It comes as figures released yesterday showed 694 registered sex offenders were living in Staffordshire on March 31 – two fewer than the previous year.

Of these, 233 were living in Stoke-on-Trent, 119 in the North Staffordshire division, which covers Newcastle borough and the Moorlands, and 186 in Chase division, which includes Stone and Stafford.

Twenty of the most dangerous sex offenders are currently subject to the lie-detector tests.

Barbara Jones, head of Stoke-on-Trent Probation Delivery Unit, said: "The purpose of the polygraph is to help us better manage the risk from certain sex offenders who are being supervised.

"Offenders are regularly asked questions about their behaviour in the community. Which offenders are chosen and the frequency of the tests depends on the circumstances of their offending and level of risk.

"They know their responses are going to be checked so it helps people to be more open about what's going on."

Each polygraph session has three phases and lasts about 90 minutes. It starts with a pre-test interview when the offender is told what questions they will be asked, which can prompt an admission in itself. The offender is then attached to the lie-detector, which monitors heart rate, sweating, brain activity and blood pressure while the questions are asked.

The operator interprets the responses, before the paedophile is asked to account for any failures.

The results cannot be used in court, but are aimed at cutting further offending and encouraging offenders to make admissions. If successful, the tests could become mandatory for all sex offenders across the country.

Marie Mitchell, pictured, chairman of Fegg Hayes Residents' Association, today welcomed the move. She said: "If sex offenders are going to be released into the community and they could be a risk to the public, then it's a good idea."

But Dr Helen Jones, criminologist at Manchester Metropolitan University, questioned how effective the tactic would be. She said: "It could be useful, but it depends what questions are asked and what resources the probation service and police have to investigate tests that show there could be some illegal activity going on.

"The results of polygraph tests are not 100 per cent guaranteed, otherwise we'd be using them to investigate a whole range of crimes."