Tour de France Drops Lawsuit Against Fan Who Caused Massive Crash With Sign

The woman who allegedly caused a massive pileup during the first stage of the Tour de France has reportedly been found and arrested ... ending a 3-day search for the spectator.

As we previously reported, a woman stepped onto the road and held a cardboard sign towards the TV cameras as the pack of riders approached on Saturday ... and made contact with German rider Tony Martin.

The hit caused a chain reaction ... with dozens of other riders crashing behind him as a result.

The spectator immediately fled the scene ... and French authorities launched a search for her, as well as a call for witnesses.

According to local reports, law enforcement believe they have found the woman responsible for starting the pileup ... and took her into custody in Landerneau on Wednesday.

FYI -- officials believe the woman caused "unintentional injuries by manifestly deliberate violation of an obligation of safety or prudence."

She is reportedly facing a fine for the incident ... and there could be further legal ramifications if a rider who was forced to retire from the race decides to file a complaint.

The Tour de France has been impacted by several major crashes since Saturday ... and it got to a point where the riders had to stage a protest in hopes of finding a middle ground with race organizers.