A senior French presidential aide is to be dismissed from his job, officials say, after footage emerged of protesters in Paris being attacked by a man wearing a police visor.
The action against Alexandre Benalla was taken after "new facts" emerged in the case, French President Emmanuel Macron's office said on Friday.
Mr Benalla is being questioned over the footage of the May Day protests.
There were calls for him to be sacked after he was identified in a newspaper.
Police are questioning Mr Benalla, an assistant to Mr Macron's chief of staff, over footage filmed by a student activist showing a woman and a man being beaten during the demonstrations on 1 May.
French newspaper Le Monde identified the attacker as Mr Benalla.
While he faces questions over the assault, prosecutors said on Friday that he is also facing charges of impersonating a police officer.
In May, a few days after the incident, Mr Benalla was given a two-week suspension, but nothing was reported to prosecutors. The BBC's Hugh Schofield in Paris says that this suggests that Mr Macron's office may have already been aware of his actions.
A source close to the inquiry said that three police officers had also been suspended on suspicion of providing Mr Benalla with surveillance footage of the demonstration in an attempt to prove his innocence, Le Monde reports.
The incident took place in a popular tourist spot at Place de la Contrescarpe in the fifth district of Paris, where about 100 people had gathered on 1 May.
The original video, posted on social media by 21-year-old Taha Bouhafs, shows a man in a police helmet who is not in uniform joining CRS riot police after clashes erupted.
He grabs a woman by the neck, charging her down the street, before both disappear off camera.
Shortly afterwards he returns to the scene, attacking another protester who had been carried a short distance by police before being left alone on the ground.
The man in the helmet can be seen grabbing the young protester around the neck, hitting him in the head and apparently stamping on his stomach when he falls to the ground.
Who is Alexandre Benalla?
Mr Benalla's main duty was to arrange security for the president's engagements.
Before he joined the presidential staff he had the role of head of security during Mr Macron's election campaign in 2017.
In that role, he was a constant companion to the future president, and archive photographs show the two men together at many high-profile public events.
Formerly an employee of a private security firm, Mr Benalla had worked with other French politicians in the past - including leading Socialist Martine Aubry and Mr Macron's predecessor in the Elysée, François Hollande.
In 2012, he was hired as a driver for Industry Minister Arnaud Montebourg.
Mr Montebourg told Le Monde that Mr Benalla was fired for misconduct after causing a car accident in the minister's presence and wanting to flee the scene.