"We are certain that we have identified the biker," Annecy prosecutor EricMaillaud said on Friday. "He is a businessman from the Rhone-Alps region, with a good reputation and above all suspicion, who had gone to do some paragliding and was on his way home."
Police have been searching for the man, who was seen by forest rangers shortly before the shooting of Saad al-Hilli, his wife Iqbal and his mother-in-law Suhaila al-Allaf near Chevaline, and released an identikit picture of him in November 2008.
He was wearing a rare type motorcycle helmet, of a type of which only 8,000 were made, but he was only tracked down after police traced all 4,000 mobile phone numbers logged in the area that day and started ringing them.
"He said he did not pay attention to all the media hype around the motorcyclist and the helmet at the time," said Maillaud.
Police have accepted his assurances that he saw “absolutely nothing” but will interview him again to see if he has remembered anything.
The couple's two daughters, aged seven and four at the time, survived the attack but the older girl was shot and badly beaten.
A 45-year-old French cyclist, Sylvain Mollier, was also killed after apparently stumbling upon the scene.
The inquiry has so far failed to find the killer.
The identikit picture led investigators to a former municipal police officer, who was found with a hoard of firearms at his home but, although he was suspected of arms trafficking, he was not linked to the murders.
British police arrested al-Hilli’s brother Zaid in June 2013 but released him the following January for lack of evidence.