PARIS • The former wife of a convicted French serial killer has said he kidnapped, raped and killed a schoolgirl who disappeared 17 years ago, her lawyer said on Friday, renewing hopes of finding a body in one of France's most notorious unsolved cases.

Michel Fourniret's ex-wife Monique Olivier gave key testimony in November last year, and in January said her ex-husband was guilty of nine-year-old Estelle Mouzin's murder - prompting Fourniret's confession in March.

But Olivier's fresh disclosure - which has resulted in her being charged with complicity - have renewed hopes of finding the schoolgirl's body that investigators failed to locate in June, despite a four-day-long thorough search of the serial killer's properties in the Ardennes.

"Monique Olivier declared to the investigating magistrate... that Michel Fourniret abducted Estelle Mouzin, kidnapped her, took her on Jan 9, 2003, to Ville-sur-Lumes to hold her captive, and raped and strangled her," Olivier's lawyer Richard Delgenes said at a news conference.

"Investigations are still needed to discover where Estelle Mouzin's body is ... but (Olivier) has not been able to give information in that regard," Mr Delgenes said.

There is a possibility that the search may pick up again, this time in the presence of the serial killer.

Michel Fourniret was jailed for life in May 2008 for the murder of seven girls and young women, but until March always maintained he had nothing to do with the disappearance of Estelle Mouzin.

The nine-year-old disappeared in January 2003 in Guermantes, 30km east of Paris, while walking home from school.

Olivier is also serving a life sentence with no possibility of parole for 28 years for her role in some of the abductions and killings.

AGENCE FRANCE-PRESSE