Another Olympic pool has turned an unappetising shade of green - and the athletes aren't happy.

A day after the dive pool at the Maria Lenk Aquatics Centre in Rio de Janeiro changed colour, the adjacent water polo and synchronised swimming pool has also changed from a crystal clear blue to a murky green.

And while Olympic organisers are insistent the change of shade had no health implications, some athletes would beg to differ with claims stinging and difficulty seeing - an issue when you have to aim a ball.

"I think they bumped up the chlorine or something because my eyes are stinging," Australian centre back Richie Campbell told Fairfax after his water polo match with Japan on Wednesday.


"It hurts at the end of the game and we'll probably get teary eyes for the next couple of hours but that's all right. It wasn't too bad in the water but now it's really starting to sting."

Although Campbell did say he'd played in worse pools.

Others were less understanding. "It's very difficult to play in this water because the chlorine is really, really strong for the eyes," said Mladan Janovic of Montenegro. "You cannot even see.".

"When they finished their matches, I saw Hungarians, Australians and also Greek players ... it was like everybody was crying."

British diver Tom Daley was another Olympian questioning the pool's colour posting his concerns to Twitter.

However, bronze medal winning Canadian synchronised diver Roseline Filion said the colour actually aided her performance, reported the Toronto Star.

Being able to see the water's surface was crucial, she said, and the usual blue often blended in with the sky. The deep green colour meant that was no longer an issue.

Nevertheless, the Canadian diving team leader Mitch Geller told reporters on Tuesday that his squad "hope it is not like a swamp tomorrow".

Rio 2016 officials have blamed insufficient chlorine and the unanticipated impact of a sudden increase in pool use.

"We expect the colour to be back to blue very shortly," Rio organising committee spokesman Mario Andrada said, adding that pool officials were partly to blame for inadequate monitoring.

There was "absolutely no risk" to swimmers from the murky green pools and blamed the unanticipated impact of increased pool use for a "sudden change in alkalinity".

Mr Andrada said both pools have been treated in a bid to remedy the problem but that overnight rainfall which continued into Wednesday could delay the process.

"We expect the colour to be back to blue very shortly," he said.

Many of the athletes will be keen for the pools' normal hue to return as soon as possible.