The trial of French actor Gerard Depardieu on sexual assault charges opened on Monday in the absence of the celebrity, who had declared himself to be ill.

His lawyer, Jeremie Assous, had said earlier that Depardieu, 75, was "extremely affected" by ill health, and that he had asked for proceedings to be delayed until he could attend in person.

"Unfortunately his doctors have forbidden him from appearing here today," the lawyer said on arrival for the trial.

He said would ask the court for a six-month suspension of the trial, which comes after numerous other complaints and with a possible second court case already lying in wait.

The actor is the highest-profile figure to face accusations in French cinema's version of the #MeToo movement, triggered in 2017 by allegations against US producer Harvey Weinstein.

Depardieu faces charges of abuse that allegedly occurred during a 2021 film shoot. The names of the two women accusing him have not been made public.

One of the plaintiffs, a set dresser now aged 55, reported in February that she had suffered sexual assault, sexual harassment and sexist insults while filming director Jean Becker's "Les Volet Verts" ("The Green Shutters") in a private house in Paris.

"I expect the justice system to be the same for everybody and for monsieur Depardieu not to receive special treatment just because he's an artist," the plaintiff's lawyer Carine Durrieu-Diebolt told AFP.

Assous said that Depardieu's defence would offer "witnesses and evidence that will show he has simply been targeted by false accusations".

He accused the plaintiff of attempting to "make money" by claiming 30,000 euros (US$32,500) in compensation.

The plaintiff told French investigative website Mediapart that Depardieu had started loudly calling for a cooling fan during the shoot because he "couldn't even get it up" in the heat.

She claimed the actor went on to boast that he could "give women an orgasm without touching them".

The plaintiff alleged that an hour later she was "brutally grabbed" by Depardieu as she was walking off the set.

The actor pinned her by "closing his legs" around her before groping her waist and her stomach, continuing up to her breasts, she added.

Depardieu made "obscene remarks" during the incident, she said, including: "Come and touch my big parasol. I'll stick it in your pussy."

She described the actor's bodyguards dragging him away as he shouted: "We'll see each other again, my dear".

"My client expects that the justice system will find Gerard Depardieu to be a serial sexual assaulter," Durrieu-Diebolt said.

The second plaintiff in Monday's case, an assistant director on the same film, also alleges sexual violence.

Anouk Grinberg, an actor who appeared in "The Green Shutters", told AFP that Depardieu had used "salacious words... from morning till night".

"When producers hired Depardieu to work on a film, they knew they were hiring an assaulter," she added.

Grinberg said that in her experience, Depardieu had "always used sexual, smutty language" -- but that his behaviour had become "much, much worse, with permission from his profession, that pays him for it and covers up his offences".

Around 20 women have now accused Depardieu of various sexual offences.

Actor Charlotte Arnould was the first to file a criminal complaint.

A judge has yet to rule on a request from prosecutors in August for Depardieu to stand trial for raping and sexually assaulting her.

An investigation is also underway in Paris after a former production assistant accused Depardieu of a 2014 sexual assault.

And actor Helene Darras filed a sexual assault complaint that fell foul of the statute of limitations.

Spanish writer and journalist Ruth Baza has accused Depardieu of raping her in 1995.

"Never, but never, have I abused a woman," Depardieu wrote in an open letter published in conservative daily Le Figaro in October last year.

Weeks later, President Emmanuel Macron shocked feminists by complaining of a "manhunt" targeting Depardieu, who he called a "towering actor" who "makes France proud".

Macron's remarks followed the broadcast by an investigative TV show of a recording of Depardieu making repeated misogynistic and insulting remarks about women.

Depardieu is the biggest star to face accusations in French cinema's #MeToo movement.

Directors Jacques Doillon and Benoit Jacquot are among the other major figures accused of sexual violence. (AFP)