World and Olympic champion Sun Yang’s hopes of competing at the Tokyo Games have been ended after the Court of Arbitration for Sport (Cas) reduced the Chinese swimmer’s ban for doping violations to four years from eight. The shorter sentence announced by the Swiss-based court means Sun will be eligible for the Paris Games in 2024 when he will be 32 years old. The 200m freestyle champion was banned after he and members of his entourage were found to have smashed vials containing blood samples taken at an out-of-competition test in September 2018. A highly controversial figure in swimming but with plenty of supporters at home, Sun had questioned the credentials and identity of the testers and has constantly proclaimed his innocence. The 29-year-old, who also won two golds at London 2012, had been boosted by the Swiss Federal Supreme Court last December upholding his challenge against the Cas panel on grounds that a judge had exhibited possible bias against Chinese people. The latest Cas panel, chaired by a different president, found that Sun had “acted recklessly” in refusing to allow the blood samples to leave. It considered the circumstances surrounding the sample collection “merited a period of ineligibility at the lower end of the range”. “Consequently, the panel concluded that a period of ineligibility of four years and three months commencing on 28 February, 2020 is to be imposed on Sun Yang,” it said. Sun served a three-month doping suspension in 2014 for taking the stimulant trimetazidine, which he said he took to treat a heart condition. Swimming’s world governing body, Fina, said in a statement that it acknowledged the Cas ruling and would enforce it “according to its terms, and in accordance with its obligations as a signatory to the world anti-doping code”. “Fina remains committed to the protection of all clean aquatics athletes worldwide and will carefully consider the 90-page award,” it added. The World Anti-Doping Agency (Wada) welcomed the ruling in a statement. “The decision by the Swiss federal tribunal to set aside the Cas award was limited to a challenge made against the chair of the Cas panel and had nothing to do with the substance of this case,” said director general Olivier Niggli. “Today’s ruling reconfirms Wada’s position in relation to the original Fina ruling, which was that there were a number of points that were inconsistent with the code. Today’s Cas ruling validates those concerns.” Australian Mack Horton, who called Sun a drug cheat at the 2016 Rio Olympics and refused to share the podium with him at the 2019 world championships in South Korea, will be at the Tokyo Games. He will not be able to defend his 400m freestyle title in Tokyo, however, after failing to qualify for the event in the Australian trials. He has been included in the squad as a relay swimmer.