(REUTERS) - Four teams at the Tour de France face a nervous week after each learning on Tuesday (Sept 8) that a staff member had tested positive for the coronavirus, as one more positive within a week would see the whole team excluded from the race.
All 22 teams set off on the 10th stage after the riders themselves tested negative, with deputy race director Francois Lemarchand waving the flag for racing to commence in place of his boss Christian Prudhomme - who it emerged had also tested positive.
French health authorities and organisers Amaury Sport Organisation (ASO) have said that should two members of a team, riders or staff, test positive for the coronavirus the whole outfit will be kicked out of the race.
The International Cycling Union (UCI) and the organisers said in a joint statement that one staff member each from French outfits Cofidis and AG2R-La Mondiale, Britain's Team Ineos and Australia's Mitchelton-Scott contracted the virus.
"One of our staffers tested positive, they were tested the day before yesterday (Sunday), and we took all the necessary measures immediately," said AG2R-La Mondiale team manager Vincent Lavenu.
"The person went home. They're a very cautious person and they were hit by bad luck."
A fourth round of testing for all teams is scheduled to take place in the next rest day in Isere on Sept 14.
The organisers said race director Prudhomme would leave the race for a week.
Another concern was that French Prime Minister Jean Castex rode in the Tour director's car for part of Saturday's stage.
Castex's office said he would be tested for the virus.
All team members, riders and staff had until 1100 GMT on Monday, the Tour's first rest day, to take a test in a mobile laboratory provided by organisers.
Four staff members of the Lotto Soudal team left the Tour two days before the start after two of them returned positive tests for Covid-19.
Riders have expressed concerns that spectators were not being cautious enough, with some of them running alongside the peloton without wearing masks.
This prompted the professional riders' association (CPA) to issue a statement asking all fans to wear masks.
Slovenian Primoz Roglic is the overall leader of the race ahead of defending champion Egan Bernal of Colombia heading into the 10th stage, a pan-flat run from Ile d'Oleron Le Chateau-d'Oleron to Ile de Re Saint-Martin-de-Re.
France has recorded nearly 31,000 deaths from the virus since the pandemic began, according to a Reuters tally.