Japanese short-track speedskater Kei Saito has tested positive for a banned diuretic in the first doping case of the Pyeongchang Olympics.
Saito, a reserve on the 5,000-meter relay team, tested positive for acetalozamide, which can be used to treat conditions such as glaucoma and altitude sickness but can also be a masking agent to disguise the use of other banned substances.