Fourniret once owned the chateau

Former chateau owner Michel Fourniret, who has admitted to nine murders - including those of seven girls - was helping police in their search.

Fourniret, 62, was linked to the 1987-2001 murders after his wife gave information to Belgian police.

The case comes days after Belgian serial killer Marc Dutroux was jailed for life for murdering teenage girls.

Fourniret has been described as the "French Dutroux".

His wife, Monique Olivier - who was put under arrest on Friday for failing to help a person in danger - was also taken by police to the chateau.

Michel Fourniret has been detained since June 2003

Fourniret had identified two areas in the grounds for forensic teams to dig in, French investigators said.

They were seeking the remains of Elisabeth Brichet, a 12-year-old Belgian girl, and of Jeanne-Marie Desramault, a 22-year-old French student.

The bodies have not yet been identified, although Fourniret had indicated where each one was buried.

About 100 police officers are surrounding the grounds, according to the French news agency, AFP.

Confessions

The BBC's Stephen Sackur in Brussels says that coming so soon after the conviction of Dutroux this case has had a huge impact in both Belgium and France.

Fourniret, a forestry worker, has been in Belgian custody since June 2003, when he was arrested on charges of kidnapping and sexual misconduct.

On Wednesday he confessed to raping and killing six girls and young women over a 15-year period - four were French, two Belgian. He admitted to two other murders on Friday.

He is also reported to have confessed to killing a man in a robbery in a France in the 1980s.

Officials say that Fourniret may have escaped arrest until now because the crimes were committed on both sides of the French-Belgian border.

He has a previous conviction for rape in France.