- 2012: Gory discovery -

On September 5, 2012, a former Royal Air Force pilot discovers three people shot dead in a BMW estate car with British licence plates in a wooded clearing near the French Alpine town of Chevaline. The body of cyclist Sylvain Mollier lies nearby.

A young girl is also discovered with head wounds near the car.

Several hours later, a younger uninjured girl is found alive hiding under her dead mother's skirt.

The next day the victims are identified as a family living near London. The Baghdad-born father Saad al-Hilli, 50, his wife Iqbal, 47, and her mother Suhaila al-Allaf, 74, were shot in the head with a semi-automatic 7.65 mm pistol.

Daughters Zainab, 7, and Zeena, 4, survived.

- Three leads -

Investigators speak of a family dispute involving a brother, Zaid al-Hilli, who contacts British police to insist on his innocence.

A witness describes seeing a white car driving wildly near the crime scene, others report a dark SUV and a motorcycle.

French authorities say possible explanations include a family dispute, the father's profession as a computer engineer, or an Iraq-related activity.

An appeal for witnesses is launched. The ballistic report says the cyclist Mollier was shot first, probably having been in the wrong place at the wrong time.

Little Zainab says she only saw one "bad guy".

- 2013: Hunt for suspects -

In April 2013 gendarmes appeal for anyone who might have seen a grey SUV near the crime scene. Thirty people come forward.

Two months later Zaid al-Hilli, the brother of Saad, is detained in Britain, but released a day later.

In September prosecutors say the murders could be related to "industrial espionage and technology transfers" in the satellite industry or a dispute over a family inheritance.

In November police release an identikit image of a motorcyclist with an unusual helmet and a goatee beard.

- 2014: Ex-policeman held -

In February 2014 a 48-year-old former policeman and arms collector, who lives in the area, is detained, but is soon eliminated from the inquiry.

In 2015 the motorcyclist is found. He turns out to be a company director who had come to paraglide in the area. He is also ruled out as a probable suspect.

- 2022: New arrest -

On Wednesday police in the Alpine town of Chambery detain a man over the killings.

The arrest will allow investigators to carry out searches at addresses linked to him and check his movements around the time of the killing, prosectors say.

They say he had already been interviewed by police as a witness in the case, but never detained.