South Korea's former world short track speed skating champion Noh Jin-kyu has died at the age of 23 after suffering from cancer.
Noh's sister, Olympic speed skater Seon-yeong, wrote on her Facebook page that he had passed away at 8pm local time yesterday.
Noh set world records in the 1,500 and 3,000 metres in 2011 and won the overall title at the International Skating Union's World Short Track Speed Skating Championships in Sheffield that year.
He had won a total of four gold medals at those Championships, including the overall title.
Noh also won a gold medal in the 1,500m at the following year's World Championships in Shanghai, along with three silver and bronze.
He discovered a benign tumor in his left shoulder in September 2013 but delayed surgery to allow him to compete at the 2014 Winter Olympics in Sochi.
So sad to hear about Noh Jin-Kyu. Short Track lost one of the greats today. He will be missed. Condolences to his family and friends. #RIP— Jorien ter Mors (@jorientermors) April 4, 2016
Noh broke his elbow in practice a month before the Games and examinations showed he had developed osteosarcoma, a type of bone cancer, with the tumor growing to 13 centimetres
Noh's condition improved with treatment and he said last year that he would like to compete at the 2022 Winter Olympics in Beijing.
His condition had worsened over recent weeks, however.
Tributes and condolences poured in today, with Dutch Olympic champion Jorien ter Mors saying on Twitter that the sport had "lost one of the greats".
Italy's Olympic silver medalist Arianna Fontana said on her Facebook page that Noh had taught her "what it means to be a true champion".