Tour de France director Christian Prudhomme must leave the race and quarantine for a week after a positive Covid-19 test but all the riders were negative, organisers announced before the start of Tuesday's 10th stage.
Prudhomme, who is asymptomatic, said he had tested negative for coronavirus three times before this year's rescheduled race started on August 29 but the positive came from the first of two in-race mass tests of riders, team staff and officials.
His role as chief organiser means he attends numerous Tour-related social events, and on Saturday he shared his car with French Prime Minister Jean Castex who visited the eighth stage in the Pyrenees.
Following news of Prudhomme's positive test it was announced Castex would undergo a precautionary test, which turned out to be negative.
The prime minister's office said he and Prudhomme had worn masks "and respected social distancing" measures.
Prudhomme, who has been in charge of cycling's showcase event since 2007, told AFP: "I leave the Tour now for a week, I'm going to do what any French employee would in this kind of case."
He added: "I'll be watching the Tour on television, something I haven't done for 15 years."
Prudhomme said he was not surprised the peloton was free from coronavirus, saying "the riders live like monks or soldiers, which is not the case with me".
- Infections in four teams -
He hands over temporary responsibility of the sport's crown jewels to former rider Francois Lemarchand, who is director of the Paris-Nice stage race.
While all the riders got the green light to continue, four staff members from four different teams -- Team Ineos of reigning champion Egan Bernal, Cofidis, AG2R and Mitchelton-Scott -- tested positive and had to leave the Tour's bio-secure bubble.
This means those teams face expulsion should they have a second case exhibiting symptoms in the next week.
Overall Tour de France leader Slovenia's Primoz Roglic said he felt a mixture of relief and joy.
"It's just beautiful that the race can go on. For the director I wish him a speedy recovery."
During Saturday's visit Castex had stressed the importance of the Tour being staged despite much of France being on red alert with the number of coronavirus infections rising.
"Living with the virus is the doctrine of the Tour and the government, but everyone must protect themselves and obey the rules so that the Tour can take place," said Castex.
"What I have seen today in the Pyrenees pleased me."
The Tour, which normally takes place in July, was moved till later in the year to allow it to take place.
The test results were announced ahead of Tuesday's spectacular run between the two Atlantic Islands of Oleron and Re, both of which are connected to the French mainland by road bridges.