PARIS • The manager of Bora-Hansgrohe has raised concerns about Covid-19 testing ahead of the Tour de France after pulling his team out of the Bretagne Classic on Tuesday because of a false positive result.

The German cycling team withdrew all of their riders from the race after one team member was notified of a positive test before Tuesday's Bretagne stage.

However, in a later statement, the team said the rider had been tested again and the result had been negative.

"It looks like my concerns are being confirmed," team boss Ralph Denk said. "It is known that PCR tests have a certain rate of error and thus produce false positive results.

"This in itself would not be a problem, if there were the possibility to check the results immediately in the case of a positive finding."

When riders are tested for doping, an A and B sample are used, and Denk believes a similar system should be used to make sure Covid-19 tests are accurate, particularly when the stakes are so high.

Two positive tests at the Tour will mean a team would be withdrawn from the blue-riband race.

"(In anti-doping tests) an A sample and a B sample are provided, precisely for this reason. If the A sample is positive, the result is checked with the B sample," said Denk, whose team are the first to pull out of a World Tour race after a positive Covid-19 test.

"In the UCI's current testing strategy, this verification is not present. We are talking about athletes who have prepared for a race for weeks or months and then might not be allowed to start the event due to a false finding."

With the Tour set to start in Nice on Saturday, Denk has called on immediate adjustments to the testing protocols. He said: "We also require certainty regarding testing procedures and strategy. If we don't have this, we will soon have serious issues, because who wants to invest in a lottery game as a serious company?"

Cycling's governing body, the UCI, has yet to comment on Denk's concerns.

Riders and team staff at the Tour will be in a "bubble" from the day they arrive in Nice. They will be tested for Covid-19 twice before the race starts and a mobile testing lab will be at their disposal.

France has seen a surge in coronavirus cases recently, although the number of people in intensive care has remained stable.

REUTERS