More concerns are popping up about next year's summer Olympics in Tokyo.
For the Paralympic Games, a test event had to be cancelled over the weekend for the swimming part of the triathlon because the quality of the water was so bad.
Organizers found the level of E. coli bacteria in the water at Tokyo's Odaiba Marine Park was more than twice the level permitted by the International Triathlon Union.
It was at level four, which is the worst.
The organizers said they will carry out a comprehensive investigation.