Two more athletes and a team member who is not in the vilage have tested positive for Covid-19 sparking fears of a cluster in the Tokyo Olympic village.
Participants are flying in from all over the world for the competition and around 6,700 athletes and officials will be staying at the Olympic village.
The Tokyo Olympics has been facing significant opposition in Japan due to the risks. International Olympic Committee president Thomas Bach said that they are "very well aware of the scepticism" and appealed for Japanese fans to show support, reported AFP.
The games will have no spectators due to the lack of support from the public and safety guidelines. The Games are set to begin on Friday, but 55 cases have been reported related to the Games so far.
Games chief Seiko Hashimoto admitted athletes are "probably very worried" about coming to Japan. He pledged full transparency over Covid cases.
Olympic Games executive director Christophe Dubi said that "mingling and crossing of populations is very limited. We keep the risk to an absolute minimum level". Athletes are tested every day to ensure that no one is infected. "We can ensure that transmission between the various groups is almost impossible," he added.
Tokyo 2020 spokesman Masa Takaya told AFP that all three athletes who tested positive for coronavirus are from the "same country and sport" and "they are in isolation". He did not reveal the team's identity or nation.
Athletes are instructed to follow social distancing and avoid movement outside the Olympic bubble. They also will have to leave Japan 48 hours after their event.