(CNN)The woman who allegedly held out a banner causing the crash of dozens of cyclists during the first stage of the Tour de France last Saturday has been identified and is undergoing police questioning, the Brest prosecutor's office told CNN.
The accident happened 45 kilometers from the finish of the first stage of the race on Saturday -- from Brest to Landerneau -- when a female spectator on the side of the road held up a big sign which caused the pile up.
It's not evident what she meant to say on the sign which said 'ALLEZ OPI-OMI !' in French and German, which translates to 'Go Grandma and Grandpa.'
According to the race's video coverage of Saturday's incident, the sign hit German rider Tony Martin who was cycling near the head of the pack. Martin fell, which led to the subsequent crash of dozens of riders behind him.
Cyclists fell en masse and the crash left bikes and bodies tangled in the road. The fall held the race up for several minutes.
Gendarmes from the Finistere region had posted an appeal on Facebook to track down the female spectator who apparently had left the scene before their arrival.
On Sunday, the Finistère gendarmerie announced the opening of a judicial investigation into "involuntary injuries with disability not exceeding three months by a deliberate violation of an obligation of safety or prudence."
The woman could face up to two years in prison and a fine of $35,000 according to the Brest prosecutor's office.
The opening stages of this year's Tour have been marred by a series of crashes.
On Tuesday, during stage four, the peloton halted the race for about a minute in a silent protest for safer racing conditions.
Riders then cycled the next 10 kilometers very slowly.