The case of the man identified only as Theo, who was sent to hospital with severe anal injuries and head trauma, threatens to revive the contentious issue of policing in France's poor suburbs, which saw the death in custody of another black man last year and major riots a decade ago.
One officer was charged Sunday with rape, while three others were charged with assault during the arrest in a gritty area of Aulnay-sous-Bois on Thursday evening.
The man suffered severe anal injuries which required surgery and was also treated for damage to the head and face in hospital. The severity of his injuries led a doctor to declare him unfit to work for 60 days.
Speaking to French television station BFM on Monday, Theo described being ordered to stand against a wall by police, who deny the allegations and say they were targeting lookouts for drug dealers.
"I saw him with his baton. He rammed it into my buttocks on purpose. I fell onto my stomach, I had no strength left," Theo explained, adding that he had also been racially abused in a patrol car afterwards.
Video footage of the arrest filmed by the police has been released.
Interior Minister Bruno Le Roux confirmed late Sunday that all four officers had been suspended during the investigation, adding that exemplary conduct and respect "must guide the behaviour of security forces at all times".
There were minor clashes and arson attacks on the vast housing estate, called "3,000", on Saturday and Sunday evening where the arrest took place. At least five people were detained, police sources said.
With tensions high, further incidents occurred Monday for a third consecutive evening. Three vehicles were set on fire and "several" arrests made, according to a police source.
A helicopter and police reinforcements had been deployed.
Calls for justice
The latest incident comes in the middle of a presidential election campaign and follows the death of 24-year-old Adama Traore in police custody in another Parisian suburb last year.
That incident led to several nights of clashes in Beaumont-sur-Oise against the police, with cars and public property also set alight. Two autopsies were unable to determine the cause of Traore's death.
A group calling itself Black Lives Matter France, an offshoot of the movement against police brutality in the United States, seized on the case and helped organise protests.
Police say they are frequently targeted by delinquents as they play a game of cat-and-mouse with gangs and drug dealers in tough parts of French suburbs.
Officers staged nationwide protests in October to denounce their ever-increasing workload, bureaucracy, outdated equipment and what is seen as lenient sentencing for those found guilty of violence against officers.
Hundreds of people incensed by the alleged treatment of Theo, a youth worker, marched Monday through Aulnay-sous-Bois. Some carried banners reading "Justice for Theo", while nearby someone had scrawled "Police, rapists" on a wall.
"He was there at the wrong time and came across some crooks," Theo's brother-in-law Johann told BFM television.
Theo's sister Aurelie called for calm but said justice must be served.
"My brother is someone who's very kind, very helpful. He works with young people, he's always bringing people together," she said.
The Socialist politician in charge of the Seine-Saint-Denis region where Aulnay-sous-Bois is located, Stephane Troussel, said Sunday that the incident raised "numerous questions".
"Although thousands of police are doing their work properly... too many arrests end in nightmares for some young people. The image of the Republic is being tarnished. We have to urgently find a solution," he said in a statement. In 2005, the death of two teenagers who were electrocuted while hiding from police in an electricity substation sparked weeks of riots. Around 10,000 cars were burned and 6,000 people were arrested.
The far-right National Front (FN), which is riding high in the polls ahead of presidential and parliamentary elections from April, urged people not to judge all of France's security forces.
The FN's anti-immigration leader Marine Le Pen rails frequently against "lawlessness" and promises "zero tolerance" of crime in the rundown suburbs which are home to many newcomers to France.
"If the facts are confirmed, then it's serious and reprehensible," the party's secretary general, Nicolas Bay, told France 2 television on Monday.
"(But) one shouldn't take advantage to heap criticism on the police who do admirable work in very difficult conditions," he added.