The Chinese Swimming Association invalidated a previous decision of including Sun Yang into Chinese Olympics preparation team, as the three-time freestyle Olympic champion is still facing an eight-year ban from competition.

Beijing Youth Daily reported on Wednesday that Sun will join Chinese national swimming team's training camp for Olympics preparation from April to June. The report came with a photo of a "No 49" document of the CSA, which showed that Sun and his coach should report to the Zhejiang Sports Bureau on April 1.

"Based on World Anti-Doping Code, Sun Yang has been banned from competition after the Court of Arbitration for Sport (CAS) made the decision," read a CSA announcement on Thursday.

"That won't change during Sun's appeal to the Swiss Federal Tribunal against the Court of Arbitration for Sport (CAS) decision. The previous No 49 document is therefore invalid."

The CSA's announcement dashed fans' hope of witnessing Sun return to the pool, although the country's swimming governing body has backed the star swimmer's appeal.

Sun was given an eight-year suspension from competition in February by the Court of Arbitration for Sport. It said Sun was in violation of doping control rules by rejecting a random drug test conducted by International Doping Test and Management on Sept 4, 2018, in his home city Hangzhou, Zhejiang province.

Sun believed in his innocence saying in a social media post that he had only refused to take the test due to questions about the testers' eligibility, and he is ready to appeal to a higher court.

Nonetheless, Sun is likely to miss the Tokyo Olympics that's postponed by the COVID-19 pandemic to 2021, and the 28-year-old celebrated career could end due to the ban.