Australian swimming champion Mack Horton has delivered an explosive claim that swimming is rife with drug cheats after breaking his silence on his podium protest against Sun Yang.

Translation problems in the doping case of Olympic swimming champion Sun Yang have delayed the expected verdict to January, the Court of Arbitration for Sport (CAS) said on Wednesday (AEDT).

CAS said an “agreed-upon written transcript” from the hearing, including Sun’s testimony from Chinese into English, is being prepared to help the judging panel who heard the appeal in open court last month.

“In view of these circumstances, the (verdict) is not expected to be issued before mid-January,” the court said.

Sun is facing a ban from next year’s Tokyo Olympics if the three-judge panel decides he broke anti-doping rules by refusing to co-operate with officials who visited his home in China in September 2018.

He disputed their credentials to take his blood and urine samples and the World Anti-Doping Agency (WADA) appealed against a ruling by swimming governing body FINA to simply warn Sun over the confrontational incident.

Lawyers and the three judges often had difficulty following proceedings, including cross-examination of Sun early in the 10-hour hearing in Switzerland as translation issues plagued the case.

CAS rules allow parties to provide their own translators, but those brought by the three-time Olympic gold medallist’s team were replaced during the lunch break by a WADA staff member.

WADA asked the court to ban Sun for between two and eight years. It would be a second violation for Sun, who served a three-month ban imposed by Chinese authorities in 2014 after testing positive for a banned stimulant.

READ: Wildest twist yet in Sun Yang case

A security guard, allegedly under instructions from Sun’s mother, smashed a vial of the swimmer’s blood to prevent it being taken away and tested when visited last year because of concerns of the officials’ accreditation.

But after the hearing last month the Xinhua News Agency, which is China’s official state-run press agency, reported one of the officials who visited Sun for his drug test was actually a builder who was friends with one of the accompanying doping control officers (DCO).

Xinhua quoted an unnamed person as saying he was at the scene but was a construction worker, not a doping control assistant (DCA), and was not taken up on his offer to testify in Sun’s hearing.

“I am a builder and I am always busy at work, day and night. No one ever trained me about the doping test, and it is unnecessary for me to undertake such training,” the man reportedly told Xinhua.

“I agreed to give my words at a video conference before the public hearing as they requested. I was ready, but no one had ever contacted me about this.”

After this claim, Sun released a social media statement to declare “the truth will never be covered by lies”.

“I want to thank the urine inspector for being honest and brave,’ Yang wrote on Chinese social media platform Weibo.

“He stood up and admitted to taking pictures of me that night. He also admitted that no one had ever taught him how to do a doping test and had no relevant training.

“I’m not worried about the final decisions of arbitration.

“I’m confident that after today, all anti-doping test agencies will stick to the rules closely, which in turn will give much better protection of the legal rights and privacy to all athletes.”

Sun became a star in China as the country’s first man to win an Olympic title in swimming. He won gold medals in the 400m and 1500m freestyle races at the 2012 London Olympics. He added gold in the 200m at the 2016 Rio de Janeiro Olympics.

In Rio, Australian rival Mack Horton called Sun a drug cheat as anger built over a three-month ban for his positive test in 2014 that some considered too lenient. The ban was initially kept secret by Chinese authorities and swimming world governing body FINA, which some accused of appearing to protect one of its biggest names in a key market.

Sun provoked more anger among rivals by winning two world titles in July while the CAS appeal was pending. Medallists from Australia and Britain refused to stand on the podium with him in Gwangju, South Korea.