South Korea has filed a protest over defending champion Park Tae-hwan's disqualification in the 400-meter freestyle event on the opening day of the Olympic swimming competition.

Swimming governing body FINA has said that Park was disqualified by a judge on the pool deck for a false start.

The FINA Bureau will hold a jury of appeal to decide the case.

Park was first to touch the wall on Saturday and appeared bewildered when told of the disqualification, saying he needed to ask his coach what happened.

Sun Yang of China led the heats, while Ryan Cochrane of Canada took the last qualifying position in eighth. Cochrane could miss out on the final later Saturday if Park is reinstated.