Five French police officers have been arrested over the death of a 27-year-old man in a Marseille riot in July, prosecutors said.
Mohamed Bendriss, who left behind a wife and two children, was killed while filming protesters during a wave of nationwide unrest that rocked France.
It was sparked by a police officer’s fatal shooting of a teenager, known as Nahel M, during a traffic check outside Paris on June 27.
Officers responded to the protests in cities and towns with force, and hundreds of people were arrested.
Following his death, Mr Bendriss’ widow and relatives spoke out to express their sorrow and appeal for justice.
Hundreds of police officers were injured in the riots that spread across France and a fireman died while trying to douse burning cars in a garage north of Paris.
But there has never been any confirmation of a member of the security forces or a protester losing their life during the demonstrations.
The five police officers, all members of the elite Raid unit, were detained in Marseille for questioning in the probe over the death of Mr Bendriss, prosecutors said.
Several civilians and police are also giving evidence as witnesses, the prosecutors added.
"He left me with two children … I find it pitiful to kill people when they have families," his widow was quoted by French media saying. The couple have a two-year-old child and she is pregnant with their second baby.
"We are just waiting for justice,” his cousin said. “We just want to know who killed him.”
Mr Bendriss is understood to have been riding a scooter and filming a protest in the southern city on the night of July 1-2 when the incident happened.
It was days after Nahel M, of Algerian and Moroccan parents, was shot in the chest at point-blank range by an officer during a traffic stop outside the capital.
The last communication Mr Bendriss had with family members was at 10pm.
He died hours after the demonstration.
His autopsy showed traces on his chest of what could be the impact of a shot from a blast ball - known in French as an LBD and commonly used by the country's police.
The investigation is the latest controversy surrounding Marseille police.
A 22-year-old man called Hedi had to have part of his skull amputated after being beaten up and fired on with an LBD on July 21 by a group of men suspected to be police officers.
Four Marseille police officers have been charged over the incident. Three have been released under judicial supervision. The fourth has been remanded in custody.
His detention caused huge controversy within the French police, and officers across the country went on sick leave as a sign of protest. But a court last week rejected the appeal against his detention.
The officer admitted in court to firing a blast ball round, reversing an earlier denial, but said he did not see anybody injured. His lawyer added that there was no proof it was his round that had wounded Hedi.
The powerful police union, Alliance, said the ruling was "incomprehensible and very unfair".