China's triple Olympic swimming gold medallist Sun Yang has been found guilty of refusing to give a doping sample and banned for eight years in an eagerly-awaited judgement from the Court of Arbitration for Sport (CAS) on Friday. The Swiss-based CAS upheld the appeal by the World Anti-Doping Agency (WADA) against the international swimming federation (FINA) and Sun, one of China's most recognisable athletes who had already served a doping ban in 2014. Sun, who was accused of refusing to provide blood and urine samples when drug testers visited his home in China in September 2018, has the right to appeal the ruling at the Swiss federal court. A vial of Sun's own blood sample was smashed with a hammer during the testing session, but the swimmer was acquitted by FINA of anti-doping violations, agreeing that testers had failed to produce adequate identification. But the ruling outraged WADA which took the matter to CAS, demanding a ban of between two and eight years for missing the out-of-competition test. CAS said its panel had "unanimously determined" that Sun had tampered with his doping control. Taking into consideration his previous doping ban, CAS said it had imposed the stiffest eight-year sanction. "The athlete failed to establish that he had a compelling justification to destroy his sample collection containers and forego the doping control when, in his opinion, the collection protocol was not in compliance with the ISTI (International Standard for Testing and Investigations)," CAS said. "It is one thing, having provided a blood sample, to question the accreditation of the testing personnel while keeping the intact samples in the possession of the testing authorities; it is quite another thing, after lengthy exchanges and warnings as to the consequences, to act in such a way that results in destroying the sample containers, thereby eliminating any chance of testing the sample at a later stage." - Significant result - WADA director general Olivier Niggli welcomed the CAS decision as a "significant result". "WADA decided to appeal the original FINA ruling having carefully reviewed it and having concluded that there were a number of points that seemed to be incorrect under the (World Anti-Doping) Code. "Today's CAS ruling confirms those concerns and is a significant result." After that initial clearance by FINA Sun was able to compete in the World Championships in Gwangju, South Korea, in July, where he won two golds but became a focus of protests from rivals, especially from Australia. CAS ruled that his results from Gwangju would stand "in the absence of any evidence that the athlete may have engaged in doping activity since 4 September 2018".