A young French campaigner, who set up an association to help victims of drugs violence and took their cause to President Emmanuel Macron, has lost a second brother to suspected criminal gangs in Marseille.

Amine Kessaci's 20-year-old brother Mehdi was parking his car in the centre of the city when a motorcycle drew up and the pillion passenger opened fire with a 9mm pistol.

Their elder brother, Brahim, was murdered in 2020. He was shot and his charred body found in a burned-out car, a common method in gang killings known locally as a barbecue.

Marseille is renowned for worsening drugs wars, with rival gangs from high-immigration neighbourhoods in the north of the city battling over turf.

While Amine's murdered elder brother, Brahim, was known to have become involved with drugs gangs, investigators say that was not true of Mehdi, who had ambitions to become a policeman.

They fear the murder was a warning aimed at Amine.

That hypothesis is absolutely not being ruled out, said Marseille chief prosecutor Nicolas Bessone on French radio.

After his elder brother's murder, Amine set up an association called Conscience, which aims to help young people in Marseille's poor estates to escape the clutches of powerful drugs gangs.

He was a high-school student at the time and then last year ran unsuccessfully for the Green Party in European and legislative elections. He recently wrote a book called Marseille Wipe your Tears – Life and Death in a Land of Drugs and now, aged 22, he lives under police protection after receiving death threats.

Amine Kessaci's association, Conscience, has branches in several other towns and cities. Its main activities involve providing help and advice to families who have lost sons in drugs violence, and creating links between ex-delinquents and employers.

When he was 17, Amine was selected to meet Emmanuel Macron when the president came to Marseille in 2021 to discuss projects to improve life in the city. A local newspaper dubbed him in its headline: The kid from the estates who has Macron's ear.