Police placed three men under formal investigation on Friday for their roles in pimping out women for sex work in several apartments.

Some of the apartments were rented out through accommodation-sharing site Airbnb, France Info reported, citing a police source.

The men were arrested in late November after the BRP — the arm of the French police force dedicated to tackling crimes of pimping — arrested another man, who had been a client of the women.

While selling sex is legal, soliciting sex or running a brothel has been illegal in France for decades, and paying for it was criminalized in spring 2016.

The man's arrest led investigators to the three men, aged between 30 and 42, who pimped out women in an apartment in the affluent eighth arrondissement and three Airbnb properties. The key suspect, a 30-year-old, has a previous conviction for procurement.

He took 50 percent of the money the women earned, Le Parisien wrote, allowing him to make €100,000 over the course of three months. Ten sex workers worked in one of the apartments, selling sexual services for between €200 and €300, and one of the women told police she had paid the men €15,000 since the summer.

Police also found illegal drugs when they carried out a search of the apartments.

Clients of sex workers can be fined up to €1,500 for paying for sex, which increases to up to €3,750 for repeat offenders, though the measure introduced last year has been criticized by some of those working in the sex industry.