Children are alleged to have been handed over to pedophiles by their parents in return for small gifts, such as a carton of cigarettes.

Three children's newspapers, which are popular with readers aged seven and above, issued special editions explaining pedophile behaviour.

"If someone suggests or forces you to do something that you refuse, if they do not respect your body, you must quickly talk about it and report your attacker," said Petit Quotidien. "A child who is attacked is not guilty of anything," it reassured its readers.

Alarm over child-sex abuse has been heightened by the mass trial of 39 men and 27 women. They are alleged to have taken part in regular orgies with at least 45 children on a housing estate between 1999 and 2002.

Aiming to stage an exemplary prosecution, the authorities have spared no expense in an investigation that has produced 25,000 pages of pre-trial evidence and testimony.

Of 39 defendants being held in custody, 13 are women. Three of the accused face possible life sentences at the end of the trial, scheduled for June. The others face lesser terms, ranging from three years for failure to report a crime to 20 years for rape.

With more than half the defendants pleading guilty, welfare organisations and the media are asking how social workers, teachers and the police failed for so long to uncover the alleged abuse of children aged from six months to 15 years.

At least three of the defendants have served prison terms for pedophile crimes. They include Eric Joubert, who was tracked down by police in 2002 to the home of Franck and Patricia Vergondy, whose children had been taken into council care. The Vergondy flat is alleged to be the centre of the child-sex trade on the estate.

In a summary of what it calls the repugnant facts of the case, the prosecution alleges that a ring of acquaintances, mainly unemployed people in their 30s, rented out their children, or paid for sex with children, in the St Leonard's district of the Loire Valley town.

Three couples alleged to be at the centre of the ring are said to have lured their children and those of their relatives "to play doctor" with the adults on Wednesday afternoons and at weekends. One young girl was allegedly raped 45 times.

"Parents of one kid sold her for a new car tyre. That is the atrocious level of barbarity," said Philippe Cosnard, a lawyer for a child protection group represented at the trial.

Experts are contrasting the thorough investigation of the Angers case with the failed prosecution of a ring of alleged child abusers from Outreau, near Boulogne, last year.

The Outreau case collapsed and the state apologised to 12 acquitted defendants who had spent up to three years in pre-trial detention. Unlike Outreau, much of the evidence in the Angers case has come from the testimony of adults. Testimony from children will be shown on video.

Defence lawyers will argue their clients suffered disorders that should have been detected by social services, who were in contact with them, and the estate families were being manipulated by middle-class "clients" who abused their children for money.

The Times