South Korea's Seo Yira (L) and Japan's Kei Saito taking part in the men's 1,500m short track speed skating heat event during the Pyeongchang 2018 Winter Olympic Games in Gangneung. Japanese short-track speed skater Kei Saito has tested positive for doping at the Pyeongchang Olympic Games. Pic/AFP

Japanese short track speed skater Kei Saito has been kicked out of the Winter Olympics after a positive doping test. This is the first doping case of the Pyeongchang Olympics. The news was announced by the Court of Arbitration for Sport, who said that the 21-year-old voluntarily accepted a provisionalsuspension after an out-of-competition test showed signs of acetalozamide, which can be a masking agent and is used as a diuretic. Masking agents are often used to cover up performance-enhancing substances. Saito, who left the Olympic Village when told of the news, said he was stunned by the failed test.