Mr al-Hilli's seven-year-old daughter Zainab was discovered badly beaten by a passing British cyclist shortly after the attack.
Her four-year-old sister, Zeena, was found unscathed hiding under her dead mother's skirt eight hours later. The family, from Claygate, Surrey, had been camping near Lake Annecy when they were attacked.
It had been thought that Mr Mollier was killed because he witnessed the shootings as he cycled past.
But Lt Colonel Benedict Vinnemann, who is leading the gendarme inquiry, revealed he was considering other possibilities.
He said: "Was the al-Hilli family the main target? Was it not the cyclist? Only ongoing work on the scene can answer this question clearly."
Were talking about someone whom everybody says was a gentleman, but who's to say he did not lead a double life?
Mr Mollier worked for Cezus, a subsidiary of the Areva Group, specialising in zirconium metalworking for nuclear fuel containers.
He lived in Ugine, close to the isolated beauty spot on the edge of the village of Chevaline where the shootings took place.
He had two teenage boys from a previous marriage while his second wife, a pharmacist, gave birth in June. Mr Mollier was still on paternity leave and had been using his spare time to cycle around the countryside.
The two survivors, Zainab and Zeena, are back in Britain and are believed to have been reunited at a secret location near London. They are being closely protected, amid fears that whoever was responsible for the attack may try to harm them.
- Daily Mail