Triathlon was cancelled on Saturday due to a polluted River Seine. GETTY IMAGES

Olympic organisers cancelled part of the triathlon training in the River Seine scheduled for Saturday due to concerns that heavy rain had likely made the water too polluted for swimming.

In a statement, Paris 2024 organisers announced that only the running and cycling segments of the triathlon mixed relay training would take place. 

The decision was made because of "the heavy rain over the last two nights, which have been particularly intense upstream of Paris, and the expected drop in water quality as a result."

French authorities have invested €1.4 billion ($1.5 billion) over the past decade to clean up the Seine, including major new water treatment and storage facilities in and around Paris.

Triathlon training has been cancelled due to a polluted River Seine. GETTY IMAGES
Triathlon training has been cancelled due to a polluted River Seine. GETTY IMAGES

However, heavy rainfall can still overwhelm the city's underground drains and sewage system, causing untreated effluent to be released into the river.

Water cleanliness has been a recurring issue at the Paris Games, with pollution causing a 24-hour postponement of the men's triathlon on Tuesday. The men's and women's events finally took place on Wednesday after pollution levels were "assessed as compliant."

The weather during the Paris Games has been highly unpredictable, ranging from heatwaves to heavy rains, such as the torrential rain that marred the opening ceremony.