The investigation opens as a wave of indignation linked to the death of George Floyd in the United States rises globally in tandem with a mobilisation in France against alleged police violence.
'Public insults'
The Paris public prosecutor's office said would focus on "public insults of a racist nature" and "public provocation of racial hatred".
The interior minister referred the case to the public prosecutor's office after the news website Streetpress uncovered a private Facebook group called "TN Rabiot Police Officiel", which was reserved for law enforcement officials .It has over 8000 members.
According to the screenshots published by the site, a large number of hateful, racist, sexist and homophobic messages were exchanged there.
Some make fun of the deaths of young men at the wheel of their motocross bikes or call singer Camélia Jordana, who recently denounced police violence, a "dirty whore".
"If they are true, these unacceptable comments are likely to seriously undermine the honour of the national police and gendarmerie," a spokesperson for the police force said.
Castaner promised a "sanction" for "every fault, every excess, every word, including racist expressions" within the police force.
"The police are policemen 24 hours a day. They must respect ethics. These discussion groups, where such venom is launched, are not tolerable," said Unsa-Police secretary-general Philippe Capon. "When the fault is proven, the black sheep must be punished."
The anti-racist association La Maison des Potes announced a complaint against X because "racism is an evil that eats more and more police".
Youcef Brakni, a member of the Justice and Truth Committee for Adama Traoré, a young black man who died in 2016 after being arrested, said the Facebook group reflected a feeling of "impunity" within the police.
‘Malaise’ in France
A recurring bone of contention in recent years, accusations of police violence coupled with racism have been resurfacing in France, in the wake of worldwide outrage over the death of George Floyd, a 46-year-old black American who was asphyxiated by a white policeman.
On Friday, government spokeswoman Sibeth Ndiaye said there was "a certain uneasiness for at least a certain part of the French people", who needed to be heard.
On Saturday, a massive demonstration protesting against alleged police violence took place in Paris
Last week in Strasbourg, several thousand demonstrators (3,500 according to the prefecture, 4,000 to 5,000 according to the organisers) dressed in black gathered to pay tribute to George Floyd, say no to racism and denounce police violence.
In Clermont-Ferrand, several hundred people also gathered on Friday shortly after 6.00 pm, this time at the call of the collective "Justice and Truth for Wissam El Yamni", who died in this city in 2012 after his arrest by the police in controversial conditions.
