Alexandre Benalla, a former security aide to French President Emmanuel Macron, was placed under formal investigation on Sunday for assaulting a protester during a May Day rally in Paris.

The attack by Benalla was caught on camera, and has sparked Macron’s first major political crisis since taking office last year.

The Paris prosecutor's office on Sunday said Benalla and four others, who have been taken into custody, have been put under formal investigation over the incident.

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The others arrested include Vincent Crase, who worked for Macron's party and was by Benalla's side on the day of the attack, as well as three police officers suspected of illegally passing footage of the events to Benalla earlier this week.

The video of the May 1 event in Paris, revealed Wednesday by French daily Le Monde, shows Benalla in a helmet with police markings. Surrounded by riot police, he brutally drags a woman from a demonstration and then repeatedly beats a young male protester on the ground. The man is heard begging him to stop. Another man in civilian clothing pulled the young man to the ground.

Police, who had removed the man from the crowd before Benalla took over, didn't intervene. Benalla then left the scene.

Earlier in the day, the prosecutor's office said that Benalla, who handled Macron's security during the 2017 presidential campaign, and Crase are now prohibited from possessing a weapon or working in public service.

Benalla was fired by the presidential palace on Friday and his apartment was raided by investigators on Saturday.

Macron silent, constitutional reforms suspended

Macron has remained silent on the topic. Instead, Interior Minister Gérard Collomb will be questioned by lawmakers this week as Macron's government faces mounting criticism of how it has handled the Benalla affair.

The uproar over Benalla's earlier punishment a two-week suspension and a change in responsibilities upended regular business in parliament. Many lawmakers are aghast that Benalla still had an office in the presidential palace two and a half months after the beating, and that he was not immediately reported to judicial authorities.

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On Sunday, the government suspended parliamentary debate of Macron’s controversial constitutional reform bill until further notice. Since Thursday, lawmakers demanding answers over the Benalla affair have effectively blocked the debate.

"The government has decided to suspend the scrutiny of the constitutional reforms; we hope that it will be able to resume later under calmer conditions," said justice minister Nicole Belloubet, whose remit includes constitutional affairs.

(FRANCE 24 with AP, AFP and REUTERS)