Image source, Central News and PicturesImage caption, Saad al-Hilli was shot dead with his wife and mother-in-law
French police have arrested a suspect over the unsolved 2012 murder of a British family and a French citizen in the Alps.
Few details were given, but police said a man was in custody "in order to do verifications regarding his schedule".
Saad al-Hilli, his wife Iqbal, Mrs al-Hilli's mother Suhaila al-Allaf and a cyclist, Sylvain Mollier, were found shot dead on a road near Lake Annecy.
The al-Hillis' two young daughters survived the attack.
Zeena, then aged four, was discovered hiding under her mother's body inside the family car.
Zainab, seven at the time, was found with serious head injuries after being shot and beaten.
The have since been given new identities and in 2020 were interviewed again to try to make progress on the case.
French investigators have explored several theories, such as a family feud or Mr al-Hilli's work as a satellite engineer, as reasons for the attack but the case remains a mystery.
A number of people have been arrested in connection with the deaths but no charges have ever been brought.
Investigators have said that Mollier had no link to the British family was simply in the wrong place at the wrong time.