Rio Olympics: Regatta waters 'substandard and unhealthy'
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.
10 Jan 2014