Prosecutors in France have opened a preliminary investigation into claims of sexual harassment made by political colleagues of senior MP Denis Baupin, reports BBC News.
Several women in the Green party have alleged they were subjected to either sexual assault or lewd text messages.
Mr Baupin, 53, who stood down on Monday as deputy speaker of parliament, has vigorously denied the allegations.
His lawyer sued two French media outlets on Tuesday for defamation, condemning the claims as "mendacious".
A number of French male politicians have been accused of sexual harassment in recent years.
The most high-profile case involved presidential hopeful Dominique Strauss-Kahn, whose career was brought to an end by New York rape charges that were subsequently dropped.
On its front page on Tuesday the daily Libération published a petition by 500 female politicians and activists demanding an end to the mafia-style silence surrounding sexual harassment in France. Their Twitter campaign group is called #levonslomerta.
Under French law, allegations of sexual harassment or aggression where the victim is an adult have to be made within three years and it is unclear how many of the revelations fall inside that period. Some of the accusations date back 15 years.
In its statement, the Paris prosecutor's office said no complaint had yet been made by any of the women. The inquiry would seek to gather evidence from the women involved "to verify the dates and places that the alleged acts took place and listen to every useful witness", it added.
According to the France Inter and Mediapart news organisations, the women speaking out against Mr Baupin had decided to come forward after Mr Baupin gave his support in March to a campaign criticising violence against women. His accusers said they were previously afraid for their careers, and did not speak out.
Mr Baupin left the Greens (EELV) last month amid disagreements over party strategy. He is married to Emmanuelle Cosse, the housing minister in Francois Hollande's Socialist government. She was sacked by the Greens when she took on the job.
Ms Cosse told France Info radio on Tuesday that she had been unaware of the allegations before they had emerged on Monday and had been very moved, as a woman as well as a wife and mother.
The housing minister said, however, that she had complete faith in her husband.
Read more of this report from BBC News.
See Mediapart's report here: