There are 306 registered sex offenders living in Oxfordshire, it was announced for the first time yesterday.

In their annual report about the number of criminals being monitored under Multi-Agency Public Protection Arrangements (Mappa), Thames Valley Police and the Probation Service gave a breakdown of the number of offenders in each county, rather than just a regional total.

However, the Probation Service said that although it knew where the offenders lived, it would "compromise risk-management plans" to reveal how many lived in Oxford or other communities.

And the service reiterated it would never bow to public pressure to disclose the whereabouts of sex offenders for fear of vigilantes taking the law into their own hands.

Paul Gillbard, director of offending for the Thames Valley Probation Area, said: "I cannot be absolutely confident as we speak where every one of the 306 is (but) if any are not at their addresses then action is taken immediately to locate them.

"What we would not be supportive of is anything that would undermine the ability of the authorities knowing where people are.

"If there was open public disclosure of the names and addresses of sex offenders, what that would do is send people underground - then people start disappearing."

Earlier this year, it was revealed that paedophile Robert Excell, who was deported from Australia, had been living in East Hanney, near Wantage. Villagers were horrified to discover he was living in their midst.

Annual data about Mappa issued yesterday showed the number of registered sex offenders in England and Wales increased by more than three per cent year-on-year, to just under 30,000.

In Oxfordshire it means there is one registered sex offender in every 1,980 people.

The report also revealed that the number of violent and other sex offenders jumped by more than 13 per cent, to 14,317. In all, 47,653 violent and sex offenders were being monitored under Mappa arrangements in 2005-6 - up almost seven per cent on 2004-5.

Child protection expert Marilyn Hawes, of www.enoughabuse.co.uk, said: "I understand the sentiment (of disclosing the whereabouts of paedophiles) but we have a knife culture in this country and you would get mis-identity. Leave it to the police."

On Monday, former Oxfordshire clergyman Richard Thomas, 56, is due to be sentenced after more than 100 indecent images were found on his computer. He has already been put on the sex offenders' register.

Mr Gillbard added: "I'm against blanket disclosure of names and addresses for everybody who appears on the register, because that's liable to increase the risk to the public and make it all the more difficult for the authorities to monitor them.

"If somebody wanted to go to ground, theoretically they could (but) it's very rare in life they could not be located by the authorities."

In Thames Valley there are 28 level three sex offenders, the most dangerous category. Five have been returned to jail for breaching conditions imposed when they were freed under licence.

How the system works

Mappa was established in 2001 and provides the statutory framework for inter-agency cooperation in assessing and managing violent and sex offenders in England and Wales.

The police, probation and prison services - supported by additional agencies including housing, health and social services - join forces to manage the risk to the public posed by dangerous offenders, including paedophiles.

Those who pose the highest risk are referred to a Multi-Agency Public Protection Panel (Mappa). Their cases are regularly scrutinised by local agencies. According to Mappa, Thames Valley has the fourth lowest number of registered sex offenders in England and Wales - 936 - which equates to 44 per 100,000 people living in Oxfordshire, Buckinghamshire and Berkshire combined.