The rules in the playbook, which the IOC and Tokyo 2020 organisers will use to ensure the Games are "safe and secure", have caused confusion for competitors who fear a positive COVID-19 test will scupper their dream of competing.

The document states all positive COVID-19 tests from athletes will be dealt with "on a case-by-case basis", and does not specify the length of the isolation period.

The IOC has said athletes who contract the virus will have to quarantine for "up to 10 days" and could be allowed to "resume their activities" if they return two negative results from two nasopharyngeal PCR tests after the sixth day and more than 24 hours apart.

The news will come as a relief to athletes who are concerned they will be ruled out of their competition as soon as they test positive for COVID-19, although the regulation could still prevent them from competing, depending on the date of their arrival and positive test.

"Any positive cases among athletes are dealt with by Japan’s health authorities following their existing protocols, which require observing a 10-day quarantine in a specially designated facility outside the Olympic Village and undergoing multiple NF-PCR tests for COVID-19," an IOC spokesperson said. 

"If after the sixth day of the isolation of the athlete, two tests come back negative with more than 24-hours between them - like any other positive case managed by the Japanese authorities - the athlete can resume their activities as long as they continue to follow the COVID-19 countermeasures."

At least seven athletes have been ruled out of competing at Tokyo 2020 because of positive COVID-19 tests as their quarantine period encompasses the date of their competition.

Four of these - beach volleyball players Ondřej Perušič and Markéta Nausch-Sluková, table tennis player Pavel Širuček and track cyclist Michal Schlegel - are from the Czech Republic.

The Czech Olympic Committee has launched an investigation into whether people failing to follow the COVID-19 rules on its chartered plane to Tokyo is responsible for the positive cases.

Chilean taekwondo athlete Fernanda Aguirre, Dutch skateboarder Candy Jacobs and American Taylor Crabb, another beach volleyball player, are also out of the Games due to testing positive for COVID-19.

South African footballers Thabiso Monyane and Kamohelo Mahlatsi, the first to test positive at the Village, and United States women's artistic gymnastics alternate Kara Eaker have also contracted COVID-19 since arriving in the country for the Games.

Athletes from several countries have been forced into isolation for 14 days after being deemed a close contact of someone who has tested positive for COVID-19.

There have so far been 110  cases of COVID-19 in Japan among people connected to the Games, postponed to this year because of the global health crisis, since July 1.