Police in the Alps have desperately been trying to solve the riddle of who murdered three members of the Al-Hilli family and a French cyclist on a quiet country road in September 2012. 

In November 2013 they released a police sketch (see below) of a mysterious biker spotted near the scene of the crime, hoping it would provide the breakthrough in the case.

However on Friday France Info radio reported that police had finally identified the man and are satisfied that he was near the murder spot by coincidence and had nothing to do with the quadruple murder.

Witnesses had given a description to police of the motorcyclist early on in the case, but it was not initially released for fear he would go into hiding.

Investigators had hoped that the helmet depicted in the sketch would prove a fruitful avenue of inquiry, since it is a rare model, used by French police during the 2000s, with only 8,000 made in black, as seen by witnesses.

However their hopes of a breakthrough were dashed after judges who interviewed the biker were satisfied with his explanation that he was in the area to go paragliding.

It is not the first time a lead in the investigation has proved to be a false hope.

In February last year an ex-policeman was detained in the first arrest in France in the case, but investigators soon ruled him out of any involvement.

And Zaid al-Hilli the 54-year-old brother of the murdered man, was arrested in June 2013 on suspicion of masterminding the killings, but police did not have sufficient evidence to charge him.

French police in the Alps are still appealing for witnesses.