Two Australian track and field athletes and a coach will remain in isolation for the duration of the Games after their contact with leading US pole vaulter Sam Kendricks, who was ruled out of Tokyo with COVID-19.
The athletes, understood to be vaulters Kurtis Marschall and Nina Kennedy, will be able to compete if they continue returning negative COVID-19 tests.
However, they and Kennedy's coach Paul Burgess will be kept away from the village.
The opening round of the men's pole vault is on Saturday, while the women's competition begins two days later.
"We made the decision to continue to isolate the three people from the track and field team as a precautionary measure," Australian team chef de mission Ian Chesterman said at a news conference in Tokyo on Friday.
"Whilst they tested negative today, we want to make sure they continue to test negative and we want to make sure that we continue to look after our team."
Chesterman said the AOC was ensuring the affected parties were very comfortable in their "isolation centre" and the athletes were able to still train and compete.
"We're doing everything we can to make their campaign now as normal as possible, albeit from a position of what is team imposed isolation.
"It's just the between competition and between training that they're going to be living in isolation centre that we've established.
"We also recognise the need to help them have their best performance on the day.
"We don't want them to have the whole Olympic campaign fall apart so we're trying to work really hard to make sure it's as good as it can possibly be for them, while also working very hard to make sure that the Olympic campaigns and all our other athletes in the village is also maintained and protected."
The remainder of the 41 Australian athletes and 13 officials had returned to "normal village life" following their temporary isolation on Thursday when the trio reported their casual contact with the double world champion.
The fully-vaccinated trio had met the American athlete and had hugged and shaken hands, Australian team doctor David Hughes said.
"In terms of level of risk, I judge it low to moderate," Hughes said.
"They were outdoors and wearing masks ... but we're not taking any chances."
Hughes said they would be tested twice daily, undergoing an antigen test and also a PCR test.
Japan is struggling to contain the highly transmissible Delta variant of the virus, with daily cases nationwide topping 10,000 for the first time on Thursday and the city of Tokyo in a state of emergency.
The track and field program started on Friday morning with 11 Australians in action on the opening day at Tokyo Stadium.
Australian Associated Press