Three members of the Australian athletics team remain in isolation at the Tokyo Olympics after close contact with American pole vaulter Sam Kendricks, who has tested positive for Covid-19.
Kendricks, the reigning world champion, has been ruled out of the Games.
The three Australian athletes had PCR tests and all returned negative results, but will remain in isolation.
A further 41 athletes briefly isolated in their rooms but no longer need to.
Those still in isolation will be allowed to train, subject to strict measures, and are expected to compete as planned.
The Olympic athletics competition starts on Friday.
"Once again, abundant caution and our strict protocols continue to keep the team safe," said Australian Olympic Team Chef de Mission Ian Chesterman.
"We will continue to be very thorough in our observance of the Tokyo playbooks and our own additional measures.
"We want every Australian athlete to be in a position to have their Olympic moment. We will continue to be vigilant."
Kendricks, 28, won Olympic bronze in Rio five years ago and had been expected to contend for a medal in Tokyo.
He won the world pole vault title in 2017 and 2019.
"In alignment with local rules and protocols, he has been transferred to a hotel to be placed in isolation," the United States Olympic and Paralympic Committee (USOPC) said.
"Sam is an incredible and accomplished member of Team USA and his presence will be missed. Out of respect for his privacy, we cannot provide more information at this time."
Kendricks' father Scott, who is also his coach, said on social media
his son is not experiencing symptoms.
Argentine pole vaulter German Chiaraviglio has also tested positive for Covid-19 and been ruled out of the Olympics.
On Thursday, the International Olympic Committee said two Olympic-related Covid-19 cases are being treated in hospital, although not in intensive care.
There have now been 198 cases among Olympic personnel, including 20 athletes.