PERPIGNAN, France (AFP) - The stepfather of a missing five-year-old French girl was charged on Thursday with unintentionally killing her, in a case that has gripped France.

The mother of the child, Cecile Bourgeon, elicited nationwide sympathy with her tale of how, pregnant at the time, she had fallen asleep on a park bench in May and had woken to find her little girl was gone.

The 25-year-old had issued a tearful appeal for help in finding her daughter, Fiona.

But both Bourgeon and her partner Berkane Maklouf, 32, were taken in for questioning on Tuesday and told investigators that the girl had died at home, prompting a police search.

The mother has been charged with four offences: failing to help a person in danger, unlawfully handling a dead body, falsely reporting a crime and interfering with a crime scene.

According to investigators, Bourgeon and her partner gave conflicting accounts of how Fiona died.

Maklouf said the child died after choking on her own vomit and that the couple panicked when they found her body in the morning.

A judicial source said Bourgeon had cracked under intensive questioning and told police that Fiona had died as a result of being hit repeatedly by her boyfriend after a heavy drinking session, and that her body had been buried on the fringes of a forest.

About 40 police officers with three sniffer dogs were called in to scour the edge of a lake south of the central city of Clermont-Ferrand to search for the body.

If convicted, Maklouf could face up to 30 years in prison.

His lawyer said he has denied the charge.