A kidnapping investigation has been opened into the disappearance of the girl, Maëlys De Araujo, who has not been seen since the early hours of Sunday morning.
Police have carried out searches of the area using a helicopter, divers, cavers, and police dogs, and have also interviewed all 180 of the wedding guests.
The dogs reportedly lost the girl's scent in the car park, leading police to the hypothesis of abduction, though prosecutors said they had not excluded any possible explanations for the girl's disappearance, “accidental or criminal”.
“Obviously, we are exploring all leads,” local prosecutor Dietlind Baudoin told a news conference more than 48 hours after de Araujo disappeared.
The wedding took place at a hall in Le Pont-de-Beauvoisin, Isère in southeastern France, which the child attended with her parents, older sister, and relatives.
Police have searched the hall's caretaker's house and car, according to a report in France Bleu, but neither that man nor anyone else has yet been placed in custody.
The hall used for the wedding. Photo: AFP
Now, police are checking the criminal records of the girl's relatives and other attendees at the wedding, as well as reviewing photos and videos taken at the party. Divers were also searching the nearby Guiers river on Tuesday.
“Given the time that has elapsed since the disappearance of the young Maelys and given the resources that have sadly been deployed in vain to find her, the criminal possibility can no longer be ruled out,” Baudoin said.
A source close to the investigation said “each passing hour” makes kidnapping more likely than the possibility that Maelys was involved in an accident or ran away.
“It's likely she got into a car,” the source told AFP.
They have also appealed for any witnesses to get in touch, and have issued the following description of Maëlys: “She is nine years old; she measures 1.3 metres and weighs 28 kilos; she has tanned skin, dark eyes, and chestnut hair.”