GENEVA -- International swimming authorities worked to protect three-time Olympic champion Sun Yang from being banned from the sport in a doping case, according to a Swiss supreme court document.

A verdict in the case against the Chinese swimmer is expected within days from the Court of Arbitration for Sport. But a federal court document shows that swimming governing body FINA supported arguments by Sun's lawyers to have an appeal by the World Anti-Doping Agency thrown out early last year in a pre-trial dispute over an alleged conflict of interest for the agency's lead prosecutor, American lawyer Richard Young.

The swimmer's lawyers appealed to the Swiss Federal Tribunal, which dismissed their procedural objections weeks before a rare public hearing held by CAS last November.

"In the course of the proceedings, the swimmer and FINA raised a plea of inadmissibility because of the allegedly late filing of the (WADA) appeal brief," said the Swiss federal ruling, dated Oct. 28.

Had Young, who previously prosecuted doping cases involving Lance Armstrong and Marion Jones and is based in Colorado, been considered ineligible for the case because of his past work for FINA, the WADA appeal could have technically missed its deadline and allowed CAS to decline jurisdiction.

Instead, Young stayed on the WADA team for the public hearing.

Sun is facing a ban of up to eight years for his alleged refusal to provide blood and urine in September 2018 in a visit by sample collectors to his home in China. WADA appealed after a FINA tribunal merely warned Sun and cited doubts about credentials shown by three sample collection officials.

FINA has faced criticism in the past, including from some top swimmers, for favoring Sun during his career. It did not announce Sun's three-month ban for doping imposed by Chinese authorities until after it ended in 2014.

The Lausanne-based FINA declined to comment on attempts to remove Young and stop WADA's case. Young did not respond to an emailed request for comment.

Months before the public hearing by CAS, Sun's lawyers and FINA asked Young to stand down from the case because of a possible conflict of interest. Young had resigned from FINA's legal commission in February 2019 to free himself for WADA's appeal, the federal court document stated.

The open-door doping hearing in Montreux, Switzerland, was streamed live for 10 hours on the CAS website.

Neither previous procedural appeal -- judged by CAS in July and the federal court in October -- was aired in the doping hearing when the sample collection incident was examined. During the late-night confrontation, a security guard eventually used a hammer to smash a container holding a vial of Sun's blood as the swimmer lit the scene with his mobile phone.

"That is pretty sensational," Young said three months ago in court. "But he [Sun] was nailed on a tampering violation before any of that happened."

Sun has denied any wrongdoing. Any ban imposed in the coming days would likely prevent him defending his 200-meter freestyle title at the 2020 Tokyo Olympics.