French Alps murders: Al-Hilli killings remain unsolved

Mr al-Hilli's two daughters survived the attack

A murder case in which three members of a Surrey family and a cyclist were killed remains unsolved one year on.

Saad al-Hilli and his wife Iqbal, from Claygate, her mother Suhaila al-Allaf and French cyclist Sylvain Mollier were shot on 5 September 2012.

The family were on holiday by Lake Annecy in France when they were attacked.

Zaid al-Hilli, Saad's brother, was arrested in June. The 54-year-old from Chessington is on bail until October.

The four bodies were found on a remote forest road in Chevaline.

Mr and Mrs al-Hilli's daughters survived the shooting.

Four-year-old Zeena was discovered under her mother's body inside the family car, eight hours after the shooting.

Her seven-year-old sister Zainab was found with serious head injuries after being shot and beaten.

Officers from the UK have been working with their French counterparts on the investigation and two Surrey Police officers are travelling to France this week for the anniversary.

Det Supt Nick May said: "The tragic events of a year ago left four people dead in appalling circumstances.

"We remain committed to finding answers to what happened that day on behalf of their families, particularly for the two young girls who lost their parents.

"This remains a complex inquiry and we continue to have a team of officers dedicated to supporting the investigation."

About 100 British and French police officers have been investigating the deaths.

The family's home in Claygate was searched by French investigators after the shootings.

In May, Surrey Police issued an appeal to help trace a vehicle, thought to be a UK-registered right-hand-drive 4x4, which was seen near the crime scene.

The car was being driven on the Combre d'Ire Road in Chevaline, near Annecy, about 20 minutes before the shooting, the force said.

Police also said at the time that the Surrey and Sussex Major Crime Team had been working closely with the French authorities on "a number of lines of inquiry" in the UK.

Saad al-Hilli and his family arrive at the Solitaire du Lac camp site on a Monday. Close to the shores of Lac Annecy, in the Haute Savoie region of France, the area is popular with British tourists. They pitch their tents next to their caravan, shown above.

A former RAF serviceman, who was on holiday in the area, was cycling on this forest road where he was passed by another cyclist, Frenchman Sylvain Mollier. Just south of the village of Chevaline, the road winds up a steep hill through a thickly forested area.

Minutes later, the British cyclist came across Mr al-Hilli's BMW in this lay-by, its engine running. There he discovered the French cyclist with a fatal bullet wound to the head and seven-year-old Zainab al-Hilli, who had been badly beaten and had a gunshot wound to the shoulder.

He put Zainab in the recovery position, called for assistance and broke the driver's window to reach in and turn off the car's engine. Inside the vehicle, Saad al-Hilli was slumped over the steering wheel. In the back were his dead wife and mother-in-law. Three of the four victims were shot in the middle of the head.

Also inside the car was Zainab's four-year-old sister Zeena, who was hiding in the back of the car under the legs of the dead women. French police on the scene were told not to disturb the crime scene and did not open the doors for fear of shattering the glass which had bullet holes in it.

Eight hours later, police re-examined the car and pulled Zeena, "terrorised and motionless", from the car. The search was made after investigators spoke to neighbours at the campsite who said there were two children. An earlier search using a thermal camera on a helicopter had not detected the child.