When the young friends rented a home in Palaiseau, a tony suburb of southwest Paris, they were looking forward to a festive Saturday evening.
But the group's gathering was interrupted by a gruesome discovery: A woman's body, decomposing in a garden near the edge of the property.
"Her body was found at the bottom of the property which opens out into a woods," a police source told Agence-France Presse, adding that the body was found "hunched in a dug-out area, her head against the ground, covered in branches and surrounded by wood stumps."
Investigators told AFP that foul play is suspected, and Bertrand Daillie, the deputy prosecutor for Evry, told the Associated Press that the body had been deliberately covered with tree branches.
The group had booked the home for the weekend using Airbnb, a popular website that allows people to find and rent out private properties all over the world.
An Airbnb spokesman told The Washington Post that the company intends to assist the investigation in any way possible.
"We have offered our assistance to the police and will help them with their investigation in any way we can," the spokesman said in an email. "We have reached out to the host and guests and will provide all necessary support. Over 80 million people have traveled on Airbnb and problems for hosts and guests are extremely rare."
Daillie, the deputy prosecutor, told France Bleu radio that the corpse was in an "advanced state of decomposition" when it was found, but lacked any identifying documents.
AFP reported that the deceased woman was white, in her 40s and clothed but missing shoes. She also had a "ring with a large stone" on her finger, AFP reported.
An autopsy performed Monday indicated that the woman had been dead for at least a month but did not determine her cause of death, according to the AP, which noted that "other forensic examinations" are scheduled for this week.
The Airbnb renters, a group of people in their 20s, were questioned by investigators Sunday. The property's owners - a family of seven that's away on vacation, according to Daillie- will be questioned by police on Wednesday, according to the AP.
The 19th century home rents for $435 per night and offers many amenities, including seven bedrooms and a swimming pool, the news service noted. The listing has been removed from Airbnb.