Sun Yang became the first Chinese swimmer to win the Olympic men's 200 metres freestyle gold medal on Monday.

Sun, silver medallist in the event in London four years ago, touched the wall in one minute, 44.65 seconds to beat South Africa's Chad Le Clos by 0.55 seconds. Conor Dwyer of the United States won bronze.

China's Sun Yang celebrates after winning gold. Credit:AP

It was Sun's second medal of the Games after silver in the 400m freestyle on Saturday.

Sun has been embroiled in controversy since just before the Games started after he splashed and taunted Australian Mack Horton in the training pool. Horton responded by calling Sun a "drug cheat".