Health chiefs on Sunday postponed Paralympics triathlon competitions after tests revealed the water in the River Seine in central Paris would be unsafe for swimming.
The 11 para triathlon events were rescheduled for Monday.
"This is subject to the forthcoming water tests complying with the established World Triathlon thresholds for swimming," said World Triathlon in a statement on Sunday.
"Paris 2024 organising committee and World Triathlon reiterate that their priority is the health of the athletes and with these conditions, the Para triathlon events cannot take place today."
Rainstorms hit Paris on Friday and Saturday causing wastewater and runoff to flow into the river, leading to a rise in bacteria levels including E. Coli.
It is the second change for the para triathlon events. They had initially been scheduled to take place on Sunday and Monday.
But they were moved to Sunday because of rain forecasts.
Changes
During the Olympic Games, the men's triathlon was postponed just hours before it was due to get under way after tests in the River Seine revealed unhealthy pollution levels. It eventually took place a day later after the women's race.
French authorities have invested €1.4 billion euros over the last decade on new water treatment and storage facilities in and around Paris to clean up the river.
Paris Mayor Anne Hidalgo takes plunge in Seine, signalling river is ready for Olympic events
But heavy downpours still overwhelm the city's underground drains and sewage system, leading to untreated effluent being released into the waterway.
After an exceptionally wet spring and start to summer, the Seine had been consistently failing water tests until the beginning of July.
Levels of the E.Coli bacteria – an indicator of faecal matter – were sometimes 10 times higher than authorised limits.
