There is fury in France over the murder of an 11-year-old girl after it emerged the principal suspect had been identified several times in the past as a potential child molester.

Lyhanna disappeared after school a week ago in the Gers area of south-west France. A body, presumed to be hers, was found on farmland near the town of Fleurance on Thursday.

A 41-year-old man named as Jérome B has been in custody since Monday. He is the father of a friend of Lyhanna, and two witnesses said they saw the girl in his car on the afternoon of her disappearance.

Amid the shock and grief, the affair took a political turn as details of Jérome B's police record were released by officials.

He had been named in four separate cases involving young girls in recent years. Two were closed for lack of evidence, and in a third he was dismissed from his job as a maintenance worker at a secondary school for "inappropriate behaviour" towards a teenager.

But the fourth affair has lit a fuse leading to the highest reaches of the justice system.

Jérome B was the object of a complaint last August from the mother of 10-year-old Rosa, who said she had been raped by him on several occasions, according to the state prosecutor in the town of Auch.

But shockingly, even though medical examination substantiated Rosa's claims, not once in the nine months since her family went to police had Jérome B been questioned by investigators.

The slowness of the French justice system is legendary. In this case, the delays were aggravated by the case having to be transferred from one jurisdiction to another.

But the French are appalled that none of the several alarm signals about Jérome B were heeded by the authorities, who seemed more concerned about following procedure than putting him out of capacity to do harm.

With presidential elections less than a year away, the affair has been seized on by likely candidates as evidence of laxity, incompetence and under-investment.

"The French people demand a reckoning," the president of the hard-right National Rally Jordan Bardella said on X. "This terrible tragedy could have been avoided if the justice system were not so dysfunctional."

"Our justice system is a failure, it should be totally reformed," said Bruno Retailleau of the conservative Les Républicains. "A society that is incapable of protecting its own children is a society which will one day start turning against itself."

On the left, Marine Tondelier of the Ecologists said the affair was a "symbol of a politico-judicial system incapable of handling the issue of sexist and sexual violence".

President Emmanuel Macron said it was "clear" that there had been failings. "It is unacceptable. We cannot look Lyhanna's family in the face and say this was properly handled."

Justice Minister Gerald Darmanin said he was "terrified" by what had happened.

"It is fair to ask why [a man] who was so obviously the object of suspicions was not kept away from youngsters... Why did no-one act, even though for months there had been complaints against him?"

The prime minister has demanded a report on what went wrong within 15 days.