The men's triathlon at the Paris Olympics has been postponed because of concerns over water quality in the River Seine.
Swimming training for the triathletes was cancelled on Sunday and Monday and the decision has been taken to move the men's race, which had been due to start at 8am local time on Tuesday, to Wednesday.
It has been rescheduled to take place at 10.45am local time, after the women's race which is scheduled to take place at 8am.
A statement from World Triathlon said Friday remains a contingency day if one or both of the races are unable to go ahead.
'Tests carried out in the Seine today revealed water quality did not provide sufficient guarantees to allow the event to be held,' read the statement.
The men's triathlon at the Olympics has been postponed because of the Seine's water quality
Training sessions for the Olympic triathlon event in Paris have been cancelled in recent days
'Despite the improvement in the water quality levels, the readings at some points of the swim course are still above the acceptable limits.'
Organizers also had the option to drop the swimming and make the event a duathlon.
More than €1billion (£840,000/$1bn) was spent on cleaning up the river in preparation for the Games.
However, organizers knew heavy rain in the days before a competition could cause the levels of the harmful bacteria E. Coli to rise.
There was hope the effects of the deluge that marred Friday's opening ceremony would have passed in time but that has not been the case.
Swimming in the Seine, which dissects the city, has been banned since 1923.
Heavy rain in the French capital over the past 48 hours diminished the quality of the water
In 1990, Jacques Chirac, then mayor of Paris, famously declared that he would make it clean enough to enter, but failed in his mission.
Earlier this month, following astonishing investment, current mayor Anne Hidalgo plunged in with a group of around 100 officials and swam around 100 metres.
However, the heavy rain which disrupted the opening ceremony has impacted on water quality levels, with the threat of pollution, in particular E.coli, a concern.
Such downfall is damaging given it can trigger problems with wastewater and water speed.
Over the weekend Tony Estanguet, the Paris 2024 chief, told a press conference he was 'very confident' that swimming in the Seine would take place.