SWIMMING training for the triathlon was cancelled for the second day in a row because of concerns over water quality, but organisers remain confident tomorrow’s men’s race will go ahead as scheduled.

Heavy rain can lead to increased levels of the harmful bacteria E coli in the Seine, despite more than a billion euros spent on cleaning up the river in preparation for the Games.

The deluge that affected Friday’s opening ceremony and continued into Saturday has had an effect, with the athletes again prevented from going into the water for the scheduled familiarisation session this morning.

Organisers released a virtually identical statement to Sunday, saying: “Paris 2024 and World Triathlon reiterates that the priority is the health of the athletes.

“The tests carried out in the Seine today revealed water quality levels that in the view of the international federation, World Triathlon, did not provide sufficient guarantees to allow the event to be held.

“This is due to rain that has fallen on Paris on 26 and 27 July and the impact it had on the Seine river.

“Given the weather forecast for the next 36 hours, Paris 2024 and World Triathlon are confident that water quality will return to below limits before the start of the triathlon competitions on July 30. As observed in July, with summer conditions, water quality in the Seine has improved significantly.”

Paris 2024 president Tony Estanguet, Paris mayor Anne Hidalgo and Marc Guillaume, the top government official for the Paris region, all took a dip on July 17 to showcase the Seine’s improved cleanliness ahead of scheduled open water events in the river.

The men’s triathlon race is scheduled for tomorrow at 8am local time (7am BST), with the women at the same time on Wednesday.

Should water quality not improve sufficiently, the races could be postponed or, in a worst-case scenario, the swimming leg cancelled, and the competition turned into a duathlon.

A decision on Tuesday’s race will be made at 3.30am Parisian time, with the reserve day for the men on Friday.