On the annual event's first day, a fan standing just off the pavement of the road posed for a camera while holding a sign. She was not watching the race and a bike ridden by Tony Martin clipped the sign, sending the race into chaos in a domino effect of downed cyclists.
Fan who caused Tour de France chaos arrested
The fan was tracked down based on "solid" accounts and questioned this week, France's Bleu Finistere radio station reported. Investigators had spoken with dozens of people since the accident, per reports, after officials east of Brest put out a call for witnesses. The fan has not been publicly identified.
The fan got on a flight after the accident and was untraceable, local media reported over the weekend. Christian Prudhomme, director of the Tour de France, said that ASO, the organizer of the race, filed a complaint against the fan that day.
Deputy director Pierre-Yves Thouault said the organization planned to sue "so that the tiny minority of people who do this don't spoil the show for everyone."
The fan held out a sign reading “Allez Opi-Omi.” It's a mix of French and German terms that roughly equate to "Go Grandpa-Grandma."
Tour de France continues
The Tour de France runs through July 18 and features 21 days of biking with two days of rest. It returns to its regularly scheduled calendar start after being pushed to August last year because of the COVID-19 pandemic.
Mark Cavendish won stage 4 with a down-to-the-wire finish on Tuesday.
More from Yahoo Sports: