Steve Canico went missing on the night of June 21-22 after officers moved in to disperse techno music fans in the western city of Nantes, who were attending a free concert as part of France's national music celebration day.
More than a dozen concertgoers fell into the nearby Loire river during the ensuing clashes, prompting accusations of excessive force by police trying to shut the party down.
An autopsy carried out Tuesday morning on the badly decomposed corpse that was found not far from the concert site on Monday confirmed it was Canico, the source said.
Footage shared on social media showed scenes of chaos as police carrying batons moved in on the revellers by the river.
???FLASH – Selon RTL, le corps retrouvé dans la Loire à #Nantes, non loin du quai Wilson, est celui de #Steve Maia Caniço. Lors de la Fête de la musique, 14 jeunes étaient tombés dans le fleuve après une opération de police controversée. L'animateur périscolaire avait 24 ans. pic.twitter.com/kxurOPmMO5
— Brèves de presse (@Brevesdepresse) July 29, 2019
Local authorities said 14 people were subsequently rescued from the water after the clashes, with Canico's friends fearing he was swept away.
Since his disappearance, posters have been put up around Nantes demanding “Where is Steve?”.
But that question quickly morphed into a slogan for a campaign around the country to highlight police brutality particularly during the recent “yellow vest” protests.
On July 20, hundreds of protesters formed a human chain along the Loire observing a minute of silence for the missing man.
Fête de la musique 2017, quai Wilson à #Nantes, un rapport révèle que la police a décidé de ne pas intervenir à cause de la dangerosité des lieux.
— Marion Lopez (@MarionLpz) July 28, 2019
France's National Police Inspectorate – which oversees the work of the police – has launched an investigation into the actions of the police in Nantes.`
There were also questions over why local authorities had allowed the event to go ahead at an insecure riverside venue without a barrier.
French police have come under fire for their heavy-handed techniques, including at a recent peaceful climate rally in Paris and at nationwide weekly protests by anti-government “yellow vest” demonstrators.
One of the main French policing unions Alternative Police, released a statement expressing their condolences to Steve's family, and expressing the wish that an enquiry into police actions looks thoroughly into the circumstances.
The union said: “If the investigation reveals proven mistakes or breaches, it is certain that sanctions will have to be imposed in line with the seriousness of the facts.