French rider Geoffrey Bouchard of the AG2R team has withdrawn from the Tour de France after testing positive for Covid-19 ahead of Saturday's 8th stage between Dole and Lausanne.
The 30-year-old Tour debutant is the first cyclist to pull out with Covid and teams have been maintaining a strict protocol of constant mask wearing.
Suffering throughout the seventh stage, Bouchard underwent an antigen test, which came back positive.
Bouchard - King of the Mountains in the 2019 Vuelta a Espana and the 2021 Giro d'Italia - he immediately isolated from the rest of the teams.
All other tests returned negative.
"During the stage, I did not feel well," said Bouchard.
"It's a huge disappointment because we were just getting to my favourite terrain, the mountains.
"It was my first Tour de France and it's sad to end it like this."
Tour director Thierry Gouvenou said organisers were ready for such an eventuality.
"We saw the figures (of infections) rising throughout France and we were put on red alert during the Tour de Suisse when 40 riders had to pull out," he said.
Half a dozen riders had to be replaced prior to the start of the Tour de France due to testing positive for Covid.
Backroom members of the teams competing have had to leave due to testing positive with Quick-Step on their third sporting director since it began in Copenhagen last week.