The mayor of Rio de Janeiro, Eduardo Paes, says he will not test the city's waters for viruses unless requested by the International Olympic Committee (IOC)

It's become a murky subject ever since a recent report compared the water in some Olympic venues in Rio to raw sewage.

Under scrutiny is Lagoa Rodrigo de Freitas where Rio de Janeiro mayor, Eduardo Paes, saw the last day's action at the FISA World Rowing Junior Championships, a Rio test event.

SOUNDBITE (English) Eduardo Paes, Rio de Janeiro Mayor:

We are going to do everything that is necessary to keep the athletes protected and safe, as we see that is happening in this test event. I mean, nobody is having any problems, everybody is very safe and happy with the water in Copacabana (beach) and here."

"We will not do any test for viruses. (Q: You're not going to do any?) No, we won't do it. That's a decision from the IOC (International Olympic Committee). If the IOC requests Rio State to do it, they will do it."

A recent SNTV investigation suggests there is a serious health risk to the 1,400 Olympic athletes who are set to compete in water at Rio 2016.

According to safety experts, water venues have dangerously high viral levels and are rife with human waste and sewage.

Dutch junior rower Marleke Keijser though, isn't too concerned:

SOUNDBITE (English) Marleke Keijser, Dutch junior rower:

"In the news, there were a lot of news about the water, that it is not healthy, not good for you. But I am still alive, so... (laughs) I think it's OK. Of course, you have to be a bit careful with not drinking the water, not putting your hands in your mouth, but if you know those things... well, I am still alive (laughs)"