After days of delays and uncertainty over water quality in the Seine River, the women’s and men’s Olympic triathlon races will go ahead on Wednesday.

Paris Games organisers said early Wednesday latest tests of the water showed compliance with quality standards, allowing the swim legs to be held in the river.

Elevated levels of bacteria in the river had pushed the men’s race originally planned for Tuesday to Wednesday, when the women’s competition is also scheduled.

Test events meant to allow the athletes to familiarise themselves with the course had already been cancelled for the same reason on Sunday and Monday.

The decision to proceed with the Seine swim legs for the triathlon competitions is a big win for the city, Olympics organisers and the athletes.

Officials undertook an ambitious plan, including 1.4 billion euros ($A2.3 billion) infrastructure improvements, to clean up the long-polluted Seine and have been steadfast in their insistence that the swimming portion of the triathlon and the marathon swimming events next week could safely be held in the river.

The water quality in the Seine is directly affected by rainfall that can lead to wastewater runoff flowing into the river.

Heavy rains fell during Friday’s Olympic opening ceremony, and rain continued for most of the day Saturday.