National Crime Squad officers recovered more than 1m images of child pornography after breaking the largest known Internet ring Wonderland in September.

Now detectives intend to take the unprecedented step of identifying the children on television or in newspapers, to ensure they are safe.

Identify victims

Normally the identity of child sex abuse victims are protected by law, but senior officers say the parents of the children might be unaware their children are at risk.

Though it is not known how old the images are, a National Crime Squad spokesman said they looked fairly new, and were likely to have been taken in the last few years.

Police from 12 countries, including Britain, will meet in the New Year to decide how to identify the 400 children.

Detective Superintendent John Stewardson, leading the investigation, said: "We are trying to protect them. We have to find out who these children are, they could still be in danger."

11 UK arrests

The National Crime Squad was formed in April to mastermind international investigations into well-known criminals living abroad.

Operation Orchard started in San Jose in California in May 1996 when a child complained that her friend's father had molested her.

In September there were co-ordinated arrests in 12 countries including Britain, America, Spain, Portugal, Italy, France, Denmark and Holland.

In Britain 11 people were arrested in connection with the Wonderland paedophile ring. They have been bailed until 18 November.