The Korea Swimming Federation has confirmed that Park Tae-hwan will face an international hearing after failing a drugs test.
The Olympic gold medallist's representatives have claimed that an injection administered by a doctor caused the failure of the test.
According to The Korea Herald, a KSF official said: "FINA told us of Park's positive test at the end of October last year. I understand FINA also directly informed the athlete as well.
"Because of FINA's regulations on confidentiality on doping tests until the penalties are determined after a hearing, we couldn't make any announcement."
The 25-year-old, who is known as 'Marine Boy', won gold in the 400m freestyle final at the Beijing Olympic Games in 2008 and followed that up with two silvers four years later in London.
