Christian Lantenois, a photographer for the local L’Union newspaper, and a reporter went to the Croix Rouge housing estate Saturday to investigate reports of a mass brawl among youths armed with baseball bats.
His colleague later him found on the ground, near the newspaper’s vehicle, bleeding from his ears.
Lantenois was rushed to hospital in a critical condition.
A 21-year-old man was brought before an investigating magistrate Wednesday on suspicion of attempted murder.
The man, an Algerian national, is suspected of having beaten Lantenois, first with his fists and then the photographer’s camera.
The attack triggered an outpouring of solidarity with the photographer, whom investigators believe was targeted because of his work.
President Emmanuel Macron’s office demanded Sunday that those behind the attack be brought to justice “as soon as possible”.
Interior Minister Gérald Darmanin also tweeted support for the newspaper “and the entire (journalistic) profession.”
The issue of French youth gang violence has been in the headlines following the fatal stabbing of two 14-year-olds in separate fights in southern Paris suburbs.