A second brother of a young French anti-drugs campaigner, Amine Kessaci, has been shot dead in Marseille in a suspected criminal gang killing.

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

Amine, a high school student at the time, then set up a association called Conscience, which aims to help young people in Marseille's poor estates to escape the clutches of powerful drugs gangs.

On Thursday, he learned that a second of his brothers, 20-year-old Mehdi, had also been murdered in the city.

Mehdi was parking his car in central Marseille when a motorcycle drew up and the pillion passenger opened fire with a 9mm pistol.

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.

Amine Kessaci, who ran unsuccessfully for the Green Party in European and legislative elections last year and recently wrote a book called Marseille Wipe your Tears – Life and Death in a Land of Drugs, has recently received death threats, and he is living under police protection.

Marseille is renowned for its worsening drugs wars, with rival gangs from high-immigration neighbourhoods in the north of the city battling over turf. Vendettas spawn successions of revenge murders, with killers sometimes as young as 15. So far there have been 14 drugs-related murders this year.

Amine Kessaci's association, Conscience, has branches in several other towns and cities with the goal of providing support and resources to families affected by drugs violence.