KUALA LUMPUR, Aug 1 — Canadian triathlon athlete Tyler Mislawchuk was shown on a live TV broadcast vomiting violently after he crossed the finish line for his Olympic event yesterday.

Mislawchuk finished ninth after finishing the gruelling triathlon race which also included a 40km bike ride and 10km run on top of a 1.5-km swim in the River Seine, amid pollution concerns.

AFP had quoted South African Jamie Riddle, who finished 25th, joking about the water quality.

"I’m definitely going to be visiting the bathroom later,” Riddle was quoted saying.

"I swallowed gallons and gallons of water, so that’s going to be a fun, post-race party.”

France and Britain had dominated the podiums in the event yesterday, which finally began in the Seine after days of suspense over whether the river would be clean enough for racing.

AFP reported that the Seine has been too dirty for swimming all week after Paris was deluged by rain during the opening ceremony of the Games on Friday, with the equivalent of a month’s rain falling over 36 hours.

The storms overwhelmed the city’s sewerage system despite a recent 1.4 billion euros upgrade, leading to discharges of untreated waste water that sent E. Coli bacteria levels spiking.

The swimming event was part to highlight efforts made by French authorities to clean up the waterway, which has been off-limits for Parisian swimmers since 1923.

Due to an exceptionally wet spring and early summer, the Seine had been consistently failing tests until the start of July.

Levels of the E. Coli — a key indicator of faecal matter — had been 10 times higher than authorised triathlon limits on some days in June.