The Court of Arbitration for Sport is to hold its hearing into China's Olympic champion Sun Yang in public.
Sun's case was referred to Cas after the World Anti-Doping Agency appealed against a decision by swimming's governing body Fina to only issue Sun with a warning when he missed an out of competition test at his home in China.
The hearing will be just the second such session to be open to the public.
Freestyle specialist Sun, 27, missed a doping test in September 2018.
In January, Fina's doping panel cleared him of wrongdoing on the grounds that testers had breached several rules, including failing to produce authorisation letters and a nursing licence.