Rio de Janeiro, April 26 (IANS): Guanabara Bay in the state of Rio could be stripped of hosting Rio 2016 Olympic sailing events if action isn't taken to clean the venue's polluted waters, an International Sailing Federation (ISAF) official has warned.

Government officials have vowed 80 percent of waste flowing into the bay will be treated ahead of the Games, but there are growing concerns about the slow progress of clean-up work, reports Xinhua.

"If we have to race all the races outside the bay, if that's what it comes to, to ensure a fair regatta, that's something we're going to explore and could do," Alastair Fox, ISAF head of competitions, said.

"We are going to review the situation and make some more recommendations - demands is probably the right word - to make sure things are done."

Last month, Rio mayor Eduardo Paes said that if necessary people would be employed to manually retrieve rubbish and waste from the bay before the Games.

According to Paes, the Olympic sailing course will avoid areas most affected by sewage and rubbish.

The 2016 Games, to be held on August 5-21, will be the first time the Olympics are staged in South America.