The admission follows a warning against rushing to introduce a version of the Megan's Law system that deals with child sex offenders.

Ex-chief constable Paul Whitehouse says the move could divert attention from people who pose an even greater risk. Megan's Law allows parents to know about paedophiles living in their area.

'Starting point'

It is known as Sarah's Law in this country, after Sarah Payne who was murdered six years ago. Home Office Minister Gerry Sutcliffe is going to the US to see how the system works and if a UK version could be introduced. John Reid also decided that paedophiles should be moved out of probation hostels next to schools.

This decision comes after the News of the World, which has led the campaign for a UK version of Megan's Law, found 60 had been housed, with government approval, at sites near schools. In a statement, Mr Reid said his "starting point" was "that information should no longer remain the exclusive preserve of officialdom". "I'm sending my minister to America to discover the best way of ensuring the controlled release of information to the public," he said. Sarah Payne's mother, Sara, said: "After six years of campaigning this is a tremendous breakthrough. I'm delighted."

Support needed

But the prime minister's official spokesman said: "The difficult thing in this is to get the balance right between, on the one hand, protecting the public and giving the public as much information as possible, and on the other, making sure that you don't have vigilantes."

He said there were no plans to import US laws immediately, "but we do need to consider how these operate".

"There is genuine concern in communities about this kind of justice and it's right and proper that the home secretary takes account of these genuine concerns," he added.

But Mr Whitehouse, the former chief constable of Sussex Police and now vice president of Nacro, the charity which deals with the rehabilitation of criminals, says he is not confident Megan's Law would work in the UK. He urged caution against rushing to legislate on the measure, adding that children were at greater risk from people they know than complete strangers.

Campaigners want a UK version of Megan's Law, called Sarah's Law

"We need, therefore, to recognise that if we make it very public where particular well known sex offenders are that we divert attention from people who could pose a much greater risk," he told BBC Radio 4's Today programme. Offenders being released from prison needed support from programmes like the Quaker-run one called "Circles of Support", which is backed by the Home Office, he said.

Anyone on the sex offenders register has to notify the authorities where they live, and if they are too near a school, action is taken, he said.

Daniel Dodson, of the National Association of American Criminal Defence Lawyers, said Megan's Law in the US had led to incidents of vigilantism by people who discovered the whereabouts of sex offenders.

'Terrible thoughts'

"Generally it just makes it really hard for them to get along in life, really hard for them to have jobs and eventually can lead to a hopelessness that almost makes it more attractive for them to reoffend," he said. However, the mother of a three-year-old who was kidnapped and sexually abused by a paedophile says she backs calls for Megan's Law. Craig Sweeney, 24, who took the toddler from her Cardiff home, received life but can seek parole after five years. The youngster's mother said if she had known Sweeney "had these terrible thoughts in his mind, he wouldn't have stepped over my door".

Caution needed

As part of the US system a number of states list offenders' details on the internet, allowing parents to enter their zip code (post code) or a name, to check if anyone on the register has moved in nearby. Shadow home secretary David Davis told the BBC that ministers should adopt a very careful approach.

"We must almost make sure we don't end up with some lynch mob law. And bear in mind we've had the Criminal Records Bureau failures, with innocent people being given apparent criminal records." Liberal Democrat home affairs spokesman Nick Clegg said: "Of course every measure should be taken to protect children from paedophiles, but this should never topple into vigilantism." Ex-home secretary Jack Straw also urged caution and said lessons learned from other countries were "not necessarily immediately translatable into this country".

Adapted from http://news.bbc.co.uk/1/hi/uk_politics/5093804.stm