Full coverage: 2016 Rio Olympics

Mack Horton, who won the 400-meter freestyle in Rio, had less than encouraging words for the second place finisher in the race. The Australian called Sun Yang a “drug cheat.”

That was in reference to the Chinese swimmer serving a three-month suspension for taking a banned heart medication. China’s Swimming Association is asking that the Aussie issue an apology over his comment.

The Chinese Swimming Association has issued a formal email that reads “We are aware of the harsh criticism from Australian swimmer Mack Horton, and the personal attack on Sun Yang. We think his inappropriate words have greatly damaged sporting ties between China and Australia, and damaged the image of Australian athletes. These comments lack manners, and we strongly ask that Horton apologize.”