Canadian triathlete Tyler Mislawchuk was spotted violently throwing up after crossing the finish line at the Olympics, having been forced to swim in the poor quality water of the River Seine. The 29-year-old was clearly exhausted after completing the energy-sapping course, which consisted of a 1.5 kilometre swim, 40km bike ride and 10km run.

Mislawchuk, who came home in ninth place, was seen vomiting just moments after finishing the gruelling race. The unsavoury moment was picked up by TV cameras, which also showed plenty of other athletes sprawled on the mat and gasping to catch their breath.

Alex Yee secured a dramatic victory in the men's triathlon to claim Team GB's fifth gold medal of the Olympics. He fought hard to close a 15-second gap on Hayden Wilde of New Zealand to improve on the silver medal he won in Tokyo three years ago.

In the women's race, Beth Potter took the bronze medal for Team GB as Cassandre Beaugrand emerged victorious from a lead group of four to claim the spoils for host nation France.

The build-up to the triathlon events was marred by the poor water quality of the River Seine following heavy rainfall in Paris over the weekend. The men's race was originally scheduled for Tuesday but was postponed until the river was declared safe to swim in. Organisers also had to cancel training sessions earlier in the week.

Swimming in the River Seine has been largely banned for over 100 years due to the high levels of pollution and the risk of disease from accidentally swallowing the water. French officials have invested heavily in making it safer in preparation for the Olympics, with about £1.2billion being spent on a regeneration project.

As recently as June, levels of E.coli in the river were 10 times higher than the acceptable level imposed by sports federations. The latest tests, which took place in the early hours of Wednesday morning, saw the bacteria level deemed safe enough for the Olympic triathlons to go ahead.

France currently lags behind the European Union’s average score for top-quality bathing water conditions. Anne Hidalgo, the mayor of Paris, recently swam in the river to highlight the clean-up efforts which have been undertaken to ensure its safety for the Olympics.

After completing her swim, she said: "It’s sweet and wonderful and the result of a lot of work. I remember at the very beginning in 2015 when we began our campaign for the Games, the international triathlon federation said: 'Why not a triathlon in the Seine? Will athletes be able to swim in the Seine?'. Today we can say they can."