PARIS (AP) — The body of a 65-year-old retired judge — the first to investigate the still-unsolved 1984 death of a four-year-old boy that transfixed France — has been found with a plastic bag over his head.

It was the latest macabre development in the cold case that took off anew in recent weeks.

The prosecutor of Mans, the town where Judge Jean-Michel Lambert lived, said Wednesday that an autopsy would be needed to determine the "precise" cause of death. A statement said no traces of violence or disorder were found in the judge's home, where his body was discovered the previous evening.

Lambert was at the center of the much-criticized probe into the drowning of Gregory Villemin, whose body was found in a river, hands and feet bound.