One of Simone Biles’ USA team-mates has tested positive for Covid-19 at the USA training camp on the outskirts of Tokyo.
The gymnast has not been named, but reports say it is a teenage member of the squad and she would likely have been training at the same facility as four-time gold medallist Biles.
Another gymnast is isolating in a hotel room as she was deemed to have been in close contact with the athlete who tested positive.
'I wouldn't change it for the world' - Biles proud of Olympics struggles
USA Gymnastics has said the infected gymnast was an alternate or replacement member, not a main team member, and her close contact was also an alternate. They also added that the rest of the team had moved to a different location and are continuing to prepare for the Olympics, which starts with the Opening Ceremony on Friday.
The USA Olympic Committee added in a statement: "The health and safety of our athletes, coaches and staff is our top priority. e can confirm that an alternate on the women's artistic gymnastics team tested positive for Covid-19.
"In alignment with local rules and protocols, the athlete has been transferred to a hotel to quarantine. Out of respect for the individual's privacy, we cannot provide more information at this time."
Czech beach volleyball player Ondrej Perusic has become the third athlete to test positive for Covid-19 at the Olympic Village in Tokyo.
The Czech Olympic Committee (COC) confirmed the news on Monday and Perusic and his partner David Schweiner are now set to miss their opening beach volleyball match on July 26.
The COC is seeking a postponement of the first match in the hope they could still compete. Martin Doktor, the COC chef de mission, said they were looking into “other options that would allow the boys to enter the tournament later, according to the rules”.
South African footballers Thabiso Monyane and Kamohelo Mahlatsi have also tested positive.
Watch every unmissable moment live from Tokyo 2020 across Eurosport, the Eurosport app and discovery+
Biles surprised by family as gymnast makes emotional return home after Olympics
Biles leaving 'the door open' for Olympic return at Paris 2024