Rio Olympics: Regatta waters 'substandard and unhealthy'
10 January 2014 Last updated at 06:29 GMT
International sailors, hoping to be selected for the Rio Olympics in 2016, are having to train in substandard and often unhealthy conditions.
Many athletes, including a large British squad, are currently taking part in a pre-Olympic regatta in Rio's Guanabara Bay.
They have told the BBC they are risking serious illness every time they compete in the highly polluted waters.
From Rio, Wyre Davies reports.
