Czech Olympic officials are looking into a cluster of coronavirus cases that are linked to a charter flight that brought a contingent of athletes and staff to Japan. The country's team has six coronavirus cases in total.A doctor who was on the flight was reportedly among the first to test positive. As of late Thursday, four athletes had also tested positive for the coronavirus.Road cyclist Michal Schlegel is the latest athlete to test positive, joining a list that includes two beach volleyball players and a table tennis player. Schlegel will not be able to compete in Saturday's Olympic road race, the Czech Olympic Committee said.Another athlete who tested positive is beach volleyball player Markéta Nausch Sluková, who will miss her match that was also slated for Saturday.The national team says it's urgently investigating the flight, which brought a large part of the Czech Olympic delegation to Tokyo last week. In a sign of how deep the suspicions about the flight run, after Schlegel's test was confirmed, only those cycling team officials who were on the charter plane were required to report directly to Tokyo for further coronavirus testing.The cluster of cases tied to the charter flight has become a big story in the Czech Republic, especially after media outlets there reported that many passengers had taken off their masks immediately after the plane took off."Prime Minister Andrej Babiš has described the situation as a scandal and unfair to the athletes," Radio Prague International reports.Much of the scrutiny is falling on a doctor who was on the flight, Vlastimil Voráček, who was reportedly not vaccinated and who has spouted outlandish theories about the COVID-19 pandemic — including the idea that people could protect themselves by gargling regularly with mouthwash, according to the news outlet Seznam Zprávy.The country's Olympic officials say they want the inquiry to focus on whether all precautions against COVID-19 were observed before, during and after the charter flight — and whether some of the plane's passengers may have failed to fulfill their responsibilities. Copyright 2021 NPR. To see more, visit https://www.npr.org.