A 30-year-old Frenchwoman is in police custody after reporting to a police station in Landerneau, Brittany, a source close to the investigation told the press agency.
She is accused of unintentionally causing injury and endangering the lives of others during this year’s opening phase peloton.
German cyclist Tony Martin was sent into a tumble on Saturday when he walked straight into a cardboard sign held up by a fan staring the other way at a television camera.
the collision caused a domino effect, wiping out several riders about 47 km (29 miles) from the end of the Brest-Landerneau stage.
Another German rider, Jasha Sutterlin, was the only cyclist to have to abandon the race but several people were injured, including spectators.
There was also a second crash about 7.5 km (4.6 miles) from the finish, which knocked down several riders, including British cyclist Chris Froome, who finished the race.
At the time, a senior race official reportedly said organizers would take legal action against the woman.
“We are suing this woman who behaved so badly,” deputy tour director Pierre-Yves Thouault told AFP news agency.
“We are doing this so that the small minority of people who do this don’t ruin the show for everyone,” he added.
Meanwhile, another huge pile-up occurred on Monday, leading the Tour de France riders to set foot collectively 1km into the fourth stage on Tuesday – literally – stopping the race for about a minute in a silent protest for a safer race conditions after accidents.
Wednesday’s fifth stage is a 27.2 km individual time trial from Change to Laval.
Tour organizers warned fans to “respect the safety of the riders” and “not to risk everything for a photo or to be on TV.”