A vast computer database with details of every child in England is to be used by the police in the fight against crime.

The £224million Contact-Point system was originally intended to ensure none of the 11million under-18s slipped through the child protection net.

But the latest government guidance reveals that it can be accessed 'for the prevention or detection of crime' and 'the prosecution of offenders'. 

A step too far? Police will be able to use the database for evidence of children's criminality

ContactPoint will include children's names, ages and addresses plus details of their parents, schools, medical records and social workers.

Ministers say it will connect the different services dealing with children, allowing police, council staff, head teachers, doctors and care workers to see more easily if one is at risk.

But the system will flag up if a youngster has contact with a youth offending team or drug abuse workers  -  effectively indicating which children have criminal records.

Officials admit the records can be checked by police for evidence of criminality, even though a report by a Commons committee last year said: 'The purpose of ContactPoint is not to support the fight against crime.' 

Critics said this was a ' shocking' extension of its original purpose and raised fresh fears about Big Brother Britain.

Liberal Democrat spokesman Baroness Miller said: 'This is truly shocking. It's exactly the definition of a police state.

'The police will have the details of a whole generation for so-called crime prevention.

'It raises a lot of issues and we haven't had a debate in Parliament about it.'

Professor Ross Anderson, a Cambridge University security expert, told the Daily Telegraph: 'This is yet another revelation about the database state that is shocking but not surprising.

'The police have always been able to look into whatever they want, but the information age changes the scale completely.'

Critics are also concerned that the Government's poor record on data security means children could be put at risk from paedophiles.

In February this year, an official review warned that the system would never be secure.

Ministers decided to create ContactPoint, to be launched later this year, in the wake of the horrific murder of eight-year-old Victoria Climbie in 2000.

She died in agony after being starved, beaten with bicycle chains, and tied up naked in a freezing North London bathroom by her aunt and her aunt's lover.

A high-profile inquiry found that there had been 12 opportunities to save Victoria but they were missed because different authorities failed to tell each other of concerns about her.

A spokesman for the Department for Children, Schools and Families insisted last night: 'This is scaremongering  -  pure and simple. To access ContactPoint for the purposes of prevention or detection of crime or for the prosecution of offenders, police would have to make a special request directly to the Secretary of State or local authority and make a case for disclosure.'