Full coverage: 2016 Rio Olympics

Chinese swimmer Chen Xinyi, whose positive doping test was revealed late Thursday. That led the Court of Arbitration for Sport to call a special session in Rio less than 24 hours later. The world tribunal ruled in favor of an immediate suspension. The athlete has accepted the verdict, but also asked for a second test on her sample, as well as a hearing.

The 18-year-old Chen tested positive for diuretic hydro-chloro-thia-zide after finishing fourth in Sunday's 100-meter butterfly. The CAS has not provided information on any process she might be able to use to appeal her ban. The Rio Olympics have been overshadowed by doping since Russia was accused of running a state-sponsored cheating program, in the weeks leading up to the Games. The CAS also upheld the suspensions of Polish weightlifter Tomasz Zielinksi, and Bulgarian steeplechase runner Silvia Danekova, during Friday's deliberations.

"Such things should be independent of sporting organizations. I think everyone thinks that's a good direction to go. But what does remain, as in the past, is that should a procedure be underway, there is no communication from us until that procedure is finished, until the athlete has gone through the process, has been informed, and then it will be communicated, in the first instance, by the Court of Arbitration for Sport," said Mark Adams, IOC Spokesman.