Tokyo Olympics | US gymnast tests positive for COVID-19

(Image: Reuters)

A female US gymnast has tested positive for coronavirus at an Olympic training camp and another team member is self-isolating, a Japanese official said on Monday.

The name of the athlete, in the same team as superstar Simone Biles, has not been given but the official told AFP she was a teenager.

The gymnast tested positive at the team's training camp in Inzai city, east of Tokyo.

It comes after Tokyo's Olympic Village -- where thousands of competitors are living in a biosecure "bubble" -- was hit by a fourth coronavirus case.

"We confirmed today that a teen athlete of the team has tested positive," said Kimiya Kosaku, an Inzai city official.

"She has been isolated with no symptoms. The woman whose name is not disclosed arrived in Japan on July 15. Another athlete has been categorised as having close contact. She is also staying alone inside her room at their accommodation."

Kyodo News said the rest of the team had moved to the Olympic Village on Monday afternoon.

The delayed 2020 Games will finally get under way on Friday, in a near-empty Olympic Stadium with Tokyo under a coronavirus state of emergency after a spike in cases.