Tokyo Olympics organizers reported the first case of COVID-19 at the athletes' village on Saturday, further stoking fears of a superspreader event.
The organizers confirmed that a visitor from abroad who is involved in organizing the Games had tested positive during a routine test on Friday.
The person's nationality was not revealed due to privacy concerns.
It's the first case found in the athletes' village, where a majority of the 11,000 competitors will be staying.
So far, more than 40 people involved in the Games, including both domestic and foreign nationals, have tested positive.
A COVID-19 cluster was also found at an Olympic hotel earlier this week.
This year's Games are being held mostly without spectators under tight quarantine rules.
A new Ipsos poll this week showed 78% of Japanese asked don't want the Games to go ahead, as new coronavirus infections surge, the medical system is strained, and only around 20% of the population is fully vaccinated.
Tokyo 2020 President Seiko Hashimoto acknowledged the public's concerns on Saturday, but reiterated the games would be "safe and secure."
Athletes are just starting to arrive for the Games, set to kick off next week.
There will be daily saliva testing for the athletes and others involved in the event, while visitors' movements are expected to be monitored and restricted.
But in a sign that those rules may be difficult to enforce, a Ugandan weightlifter went missing from his team's training site in Osaka on Friday.