French public prosecutor Eric Maillaud has confirmed that Patrice Menegaldo, who committed suicide last year, is a "real suspect" in an interview for The Perfect Crime, a book to be published by Britain's Daily Mirror next week.
He had been interviewed as a witness in the killing of Saad al-Hilli, his wife Iqbal, his mother-in-law Suhaila and French cyclist Sylvain Mollier because he knew Mollier's partner, Claire Schutz.
But when he killed himself last year he left a note saying that he could not bear being seen as a suspect.
That, and the fact that the victims were shot at point-blank range by a trained marksman, has aroused investigators' suspicions.
“We are talking about a hardened ex-soldier, someone using a gun, suddenly saying he couldn’t deal with being thought of as a suspect," Maillaud told the Mirror's reporters. "The investigators are still digging into this man. He had psychological problems.
“Could it, by chance, have been him? Did he regret his actions afterwards and take his own life? Otherwise it is an inexplicable suicide. He had the technical capacity to do what was done that day.”
Menegaldo lived in the same town as Mollier, Ugine, and Maillaud said that a "local killing" was "at the top of the chain" of suspicion.
That would imply that Mollier was the real target, the Mirror says.
Al-Hilli's brother, Zaid, who was briefly a suspect himself, claims Saad was "in the wrong place at the wrong time" and has accused investigators of a "cover-up".
"I think they twisted it around," he told the Mirror. "It’s not fair on the families and the victims this went on for such a long time with not a shred of evidence.
“There is a cover-up. I think they know who is behind it, who is the gunman and everything. It’s absolute nonsense what they came out with. I think they know exactly who was the target and it was Sylvain Mollier.”
In a further twist, the book says that Iqbal al-Hilli kept in touch wit her "secret" American ex-husband, Jimmy Thompson, long after remarrying, according to his sister, Judy Weatherly.
Thomspon died of a heart attack on the same day as the massacre.