SEOUL (REUTERS) - South Korea's Olympic swimming champion Park Tae Hwan will face an international doping hearing on March 23 in Lausanne, the Korea Swimming Federation (KSF) said on Friday.

Park, who became the first South Korean to win an Olympic swimming medal when he powered to gold in the 400 metres freestyle at the 2008 Beijing Games, failed in late January a doping test taken in early September ahead of the Incheon Asian Games.

The hearing had originally been set for Feb 27 but swimming's international governing body Fina had agreed to postpone it to give him more time to prepare.

A KSF official, who did not wish to be named, told Reuters by telephone on Friday that FINA had notified the federation that the hearing had been rescheduled for March 23.

The official added that four KSF officials, including the federation president, would travel to Switzerland for the hearing.

Despite some media reports, the official added that Park had yet to return to training.

Park, a two-time world champion known as "Marine Boy" in South Korea, had been left "shocked" by the positive test, which local media said had been a result of a local hospital giving him an injection that contained testosterone.

Seoul prosecutors have charged a doctor with professional negligence, according to Yonhap news agency.

Testosterone is on the World Anti-Doping Agency's list of banned substances and Park could face a lengthy ban that would prevent him from competing at the Rio Olympics next year.

At his home Asiad last autumn, he failed to win a title, ending with a silver and five bronzes.