The four men, who include the holiday camp director as well as two temporary employees who work at a leisure centre, reportedly photographed themselves in a series of poses mimicking the shocking jihadist executions that have been posted online.
In one of around 20 photographs, one of the activity leaders pretends to be a hostage kneeling on the ground with a newspaper in his hands, flanked by masked executioners holding a knife to his throat.
The photos were allegedly taken between August 4th and 21st at the holiday camp for children aged eight to 12 in a resort on the island of Groix, which is owned by the town of Colombes in southern Brittany.
Around 45 children attended the camp, supervised by around ten entertainers.
It is not clear whether any children were present when the mock beheading took place.
On Thursday Mayor of Colombes Nicole Goueta filed an official legal complaint with a Nanterre prosecutor for glorifying terrorism.
The four were also suspended from their posts and they will also be subject to disciplinary proceedings.
“I hope that the children were absent at the time of the photos,” Goueta was quoted as saying by Le Parisien. “But these are entertainers, educators. People from Colombes entrust their children to their care. It’s unacceptable behaviour.”
The mayor said she first became aware of the photos while preparing an exhibition with photos from summer camp vacations in August at a resort owned by the town on the island of Groix.
“They gave us a USB key with these pictures in which they simulate acts of torture and barbarism. There are 18. On one of them we see a child in the corner, sitting on the ground with a terrified look. But we only see the entertainer’s foot.”
She added that it was up to police to establish the intentions of the four men.
“As for the rest, it’s up to the police and justice to decide whether these managers are open to the theories of radical Islam.”
The revelation of the photos comes as France grapples with homegrown jihadism, with several nationals seen in videos released by the Islamic State insurgent group in Iraq and Syria.