Three German open water swimmers are sick after racing in the Olympic 10 kilometer race in the River Seine, the German Olympic Sports Confederation (DOSB) said, Ednews informs referring to dpa.

The river was used for the Olympic open water/marathon swimming and the triathlons despite repeatedly failing pollution and faeces tests either side of competitions.

"Two German open water swimmers received outpatient treatment yesterday for nausea, vomiting and diarrhoea. They have been feeling much better since this morning," the DOSB told dpa in a statement.

"Another swimmer with similar symptoms is currently being treated by the German team doctors."

The DOSB did not disclose names but 2023 double world champion Leonie Beck, 27, said on Instagram she had vomited nine times and has diarrhoea.

The European champion finished ninth in Thursday's race in the Paris river. There was no confirmation that her illness was linked to her swim through the river.

Beck had said after Thursday's race: "I hope we don't get anything from it."

Germany's Leonie Märtens also took part in the competition while Oliver Klemet won the silver medal in the men's race the following day. Tokyo Olympic champion Florian Wellbrock came eighth.

Media reports in Belgium last week said one of their swimmers also fell ill after swimming in the Seine during the triathlon.