Work has been done to clean up the river, but adverse weather could see the swim leg delayed or even cancelled.

The prospect of heavy rain raising e-Coli levels is one of the “bigger challenges” according to Tony Estanguet, President of the Paris 2024 Olympics.

“We are working hard on it; you know it’s one of the bigger challenges,” Estanguet told Sport Accord.

“When we decided to have this competition in the Seine, we knew it would be a big challenge, but with the authorities, there is a big programme of investment, and when we talk about legacy, this project is fantastic.

“And we are still confident that the triathlon will be based in the Seine because we have contingency plans. 

“We can postpone for rainy conditions. Because it’s programmed at the beginning of the Games we can wait for better conditions. So we are confident that it will be possible to use the Seine.”

There is no alternative venue for the Triathlon water-based events if the Seine is unable to be used.