A French water charity sounded the alarm on April 8 about pollution in the Seine just over 100 days before the start of the Olympics when the river is set to be used for swimming events.
Surfrider Foundation said it had analysed six months of tests over winter undertaken by a laboratory and had concluded that the river water remained polluted and potentially dangerous.
In an open letter, the Biarritz-based charity said it "wanted to share with stakeholders its rising concerns about the quality of the Seine but also the risks faced by athletes moving in contaminated water."
