A Covid-19 case has been recorded at the Olympic Village for the Tokyo Games, organisers said.
Tokyo officials including Seiko Hashimoto, the president of the organising committee, confirmed the case and said the positive test was Friday and is not an athlete.
Organisers said they can only offer a vague description and few details for confidentiality purposes.
“In the current situation, that positive cases arise is something we must assume is possible,” said Toshiro Muto, the CEO of the Tokyo organising committee.
The person is identified simply as “Games-concerned personnel”, and has been placed into a 14-day quarantine.
The Olympic Village on Tokyo Bay will house about 11,000 athletes during the Olympics and thousands of other staff.
IOC President Thomas Bach said this week there was “zero” risk of athletes in the village passing on the virus to Japanese or other residents of the village.
Some 1,271 Covid-19 cases were recorded in Tokyo on Friday, compared with 822 at the same point last week.