The British sprinter CJ Ujah has been provisionally suspended for an anti‑doping rule violation after testing positive for two banned substances after winning a silver medal in the 4x100m relay at the Tokyo Olympic Games. The news means that the Team GB men’s 4x100m relay team all face being stripped of their medals, with Canada being upgraded to silver and China receiving bronze unless Ujah can adequately explain how the substances got into his body. If the suspension is upheld it would be the biggest doping scandal in British Olympic history, and will take some of the gloss off Team GB’s 65-medal haul in Tokyo. Ujah, meanwhile, would likely face a four‑year ban. The news was confirmed by the Athletics Integrity Unit, which said a test on Ujah in Tokyo had shown the “presence/use of a prohibited substance (ostarine and S-23)”. Ostarine and S-23 are classified as part of a new class of drugs called selective androgen receptor modulators (Sarm). They are known to mimic testosterone by binding to hormone receptors in specific parts of the body. Ostarine is used to treat muscle wasting and osteoporosis, while S‑23 is said to target the muscle and bone tissues to promote muscle growth and bone health. Both are banned under the World Anti-Doping Agency’s list of prohibited substances. In 2017 the US Anti-Doping Agency warned athletes that ostarine was appearing in tainted supplements. The International Testing Agency, which collected Ujah’s sample in Tokyo, later confirmed it had come from an in-competition test following the 4x100m relay final. “The result was reported by the Wada-accredited laboratory of Tokyo on 8 August 2021,” it said in a statement. “The athlete has the right to request the analysis of the B-sample. “If requested by the athlete and if the B-sample analysis confirms the adverse analytical finding … the case will be referred to the anti-doping division of the court of arbitration for sport for adjudication. “It will consider the matter of the finding of an anti-doping rule violation and the disqualification of the men’s 4x100 relay results of the British team,” it said. The ITA also confirmed that, under World Athletics and IOC rules, if one athlete in a relay team was banned “the relay team shall be automatically disqualified from the event in question, with all resulting consequences for the relay team, including the forfeiture of all titles, awards, medals, points and prize and appearance money”, and said: “Given that the case is under way, there will be no further comments during the ongoing proceeding.” The AIU said that other three athletes had also been suspended: the Moroccan-born 1,500m runner Sadik Mikhou, who represents Bahrain, the Georgian shot-putter Benik Abramyan and the Kenyan sprinter Mark Otieno Odhiambo. The AIU said it worked closely with the ITA during the Games and provided the intelligence to carry out specific target testing on two of the four athletes. The British men’s quartet of Ujah, Zharnel Hughes, Richard Kilty and Nethaneel Mitchell-Blake missed out on the 4x100m title by just a hundredth of a second in Tokyo, as the anchor-leg runner Mitchell-Blake was overhauled on the line by Italy’s Filippo Tortu. None of the other Britons in the race have previously tested positive for a banned substance. The news sent shockwaves around athletics and Olympic circles. Two other leading British sprinters, Linford Christie and Dwain Chambers, have previously been banned for doping but never at an Olympic Games. Meanwhile at the 2002 Winter Olympics, the Scottish skier Alain Baxter was controversially stripped of a bronze in the men’s slalom after a banned substance was found in his urine. It later transpired that it was in a nasal inhaler purchased in the US, but that the same inhaler bought in the UK did not contain the illegal substance. Speaking before the Tokyo Games, Ujah had revealed how Zen Buddhism and morning meditation had helped him to return close to his best in 2021 after an underwhelming few years since 2017, during which he had won both the Diamond League title and a 4x100m world championship gold medal. “Since January I have listened to a lot of podcasts and an audiobook which is just looking at Zen Buddhism, that state of meditation. Those are things I’m kind of into and it’s helping me. It’s about remaining calm in situations where it may not be so calm. This is the most confident I’ve ever felt in my track career.”