The al-Hilli’s daughters Zeena, four, and Zainab, seven, survived the attack near Lake Annecy.
Now it has emerged that ammunition which would fit the Luger P06 pistol used in the Alps murders was found at the home of a man arrested over the failed attempt to kill corporate coach and hypnosis expert Marie-Hélène Dini, 55, near Paris.
According to police, Ms Dini just missed being shot by a hit squad hired by a professional rival, who allegedly paid more than £60,000 to have her killed.
Officers arrested two men armed with a military-issue pistol and silencer who were waiting in a car outside Ms Dini’s home in July last year, following a call from a suspicious neighbour.
At the time, the men falsely identified themselves as part of the General Directorate of External Security, the French equivalent of MI6.
They claimed to be on an official mission to kill Ms Dini because she was implicated in something involving Mossad, the Israeli secret service.
Detectives have long pinned hopes on tracing the 7.65 calibre bullet casings found at the scene of the al-Hilli killings.
They have spent years trying to identify the source of the 21 bullets fired from the weapon, a gun formerly used by Swiss soldiers.
The al-Hillis were shot dead at point-blank range in their estate car. Daughter Zainab was shot once, but survived.
Zeena hid under her mother’s skirt in the back of the car until she was discovered many hours later.
In 2013, Saad’s older brother Zaid was arrested by Surrey Police on suspicion of ordering his brother’s murder, but was released without charge.
He welcomed the latest development in the case.
He said: “I think this is plausible.
"I have always believed [the cyclist] Sylvain Mollier was the target, and it was an assassination that went badly wrong.
"I think there is no other explanation.
"I always believed there was a cover-up.”
Several men have been charged over the attempted murder of Ms Dini, including one identified as Daniel B, thought to be head of the hit squad.
He is a retired police officer who had worked in the police intelligence service.
Daniel B identified the client in the contract as Jean-Luc AB, a business coach who had a grudge against Ms Dini over her bid to create a professional association of corporate therapists.
Daniel B said he and Jean-Luc AB knew each other as members of a Masonic lodge near Versailles.
The former inspector reportedly claimed to be part of a “tiny group of freemasons who had turned their hands to carrying out hit contracts”.
It has also been reported that Daniel B admitted to taking part in a separate case, the murder of racing driver Laurent Pasquali, 43, in September 2019.Follow the Official Rokna NEWS Telegram Channel For More and fresh NEWS.