GENEVA • Chinese swimmer Sun Yang will get the rare public trial he asked for to answer an appeal by the World Anti-Doping Agency (Wada) that could lead to his ban from the Tokyo 2020 Olympics.

The open hearing by the Court of Arbitration for Sport (CAS) will probably be in Switzerland but is "unlikely to be before the end of October", the court said on Tuesday.

Wada has appealed to CAS against a decision by swimming's governing body Fina to clear Sun of wrongdoing during a random drug test last September.

Documents leaked to the media before the world championships in South Korea last month revealed that Sun questioned the credentials of the testers before members of his entourage smashed the vials containing his blood samples with a hammer. The 27-year-old has denied any wrongdoing.

Swimmers from Australia, Britain and the United States objected to the Chinese competing in Gwangju while the appeal case was pending. After he won the 200m and 400m freestyle, Mack Horton of Australia and Duncan Scott of Britain made silent protests on the podium. Other swimmers backed the protests publicly.

But Sun said he had acted in the "interests of all athletes" and claimed he was subjected to "insults and slander". His lawyers said last month that he wanted a public hearing to clear his name.

"At the parties' request, the hearing, which will likely take place in Switzerland, will be open to the public (including the media)," CAS said, adding that the original hearing scheduled for next month will be delayed by several weeks due to "unexpected personal circumstances involving one party".

China's first Olympic swimming champion won two gold medals at the 2012 London Olympics and one in Rio de Janeiro four years later.

He served a three-month ban in 2014 for a positive drug test, involving a stimulant trimetazidine, which he said he took to treat a heart condition.

A second doping violation would inevitably bring a harsher sanction, possibly a lifetime ban, and would rule him out of next year's Tokyo Olympics.

The CAS hearing should be the first in public since the European Court of Human Rights last year said athletes should have more rights to open the court to scrutiny.

Sun is the only athlete after another three-time Olympic swimming champion, Michelle Smith of Ireland, to opt against a closed-door hearing in the sports court's 35-year history.

She challenged a four-year ban imposed by Fina in 1998, two years after the Atlanta Olympics, for allegedly tampering with a urine sample by adding alcohol.

A panel of three CAS judges heard the case over two days in May 1999 in its home city Lausanne, Switzerland, and upheld the original verdict.

ASSOCIATED PRESS, REUTERS