A test run of Sarah's Law – the controversial scheme which allows parents to check whether people with access to their children are child sex offenders – has shown that one in 15 people enquired about are convicted paedophiles.
The figures were disclosed as the Government announced that the scheme, which has been running since September 2008 in four police force areas, will spread across the country from March next year.
Parents across Britain will be able to ask about the criminal history of neighbours, family members and anyone else who has regular contact with their children to find out if they are one of the 32,336 registered sex offenders in England and Wales.
The pilot scheme results show that, in 18 months, 585 enquiries were made to the police in Cleveland, Warwickshire, Cambridgeshire and Hampshire. Of those, 315 were investigated by police and 21 turned out to relate to people who are on the sex offenders' register for offences against children. A further 11 related to people with criminal convictions for other offences, such as violence.
The apparent success of the pilot has prompted the Home Office to extend the scheme to 18 other forces by August this year and nationally by spring 2011. The Home Secretary, Alan Johnson, said: "I am determined to do all I can to protect children and families from sex offenders. The UK already has one of the most robust systems in the world for the management of sex offenders. The new scheme will build on this, ensuring more children are kept safe.
"We've already seen that children are better protected and sex offenders more effectively managed because of this scheme, which is why it is rolling out nationwide."
The scheme is a watered-down version of Megan's Law in the US, which actively publishes the names and addresses of convicted paedophiles.
Under the UK scheme parents can ask the police about anyone with access to their children. After investigating their concerns, officers will reveal details confidentially only if they think it is in the child's interests. Police may also warn parents if concerns are raised by grandparents or neighbours.
The adoption of the scheme nationwide will be seen as a victory for Sara Payne, whose daughter Sarah was killed by the convicted paedophile Roy Whiting in July 2000. Since then she has led a campaign calling for a British equivalent of Megan's Law.
Ms Payne, who is now the Government's official Victims' Champion, and is recovering from brain surgery, said: "I am delighted that the years of campaigning and hard work by so many friends and colleagues have provided those who care for children with the right to check that adults who have access to them do not pose a danger."
The findings from the 18-month pilot scheme also showed that the most frequent users of the scheme were people asking for information on their ex-partner's new partner, which was the case in 27 per cent of the calls. Concerns about neighbours accounted for 25 per cent of the calls, while those requesting information about family members also made up 25 per cent.
The report highlighted actual scenarios which had prompted calls to the police, who then disclosed information about individuals. In one case a neighbour giving sweets to youngsters was complained about by a parent and found to be a paedophile. He was arrested for breaching a court order which barred him from contact with children.
In another scenario a grandparent had concerns about their daughter's new partner whom they believed to be acting strangely around their grandchild. Checks showed the man was not a child sex offender but did have an extensive history of violence and use of weapons.
The report, due to be published today, said that convicted sex-offenders in the pilot areas were spoken to during the scheme. A common reaction, according to the report was "one of anxiety relating to potential negative reactions in the community".
The report pointed out that parents too were anxious when the person they suspected turned out to have a child sex conviction. It said: "A number of applicants had been left to cope with difficult situations... including having to continue to live near the person they were concerned about."
Shaun Kelly, head of safeguarding at the charity Action for Children, said it was important the project was properly resourced to make sure it was appropriately monitored.