LAUSANNE, Switzerland (AFP)— Great Britain were Friday stripped of their silver medal in the men’s 4×100 metres relay at last year’s Tokyo Olympics after CJ Ujah was found to have committed a doping violation.

Ujah tested positive for the prohibited substances ostarine and S-23, commonly used to build muscle, after the race on August 6.

The British team just lost out to Italy for the gold medal in Japan. Canada are expected to be awarded silver, with China promoted to the bronze-medal position.

A statement from the Court of Arbitration for Sport’s anti-doping division said: “Ujah is sanctioned with the disqualification of his results in the 4x100m sprint relay final… together with the forfeiture of any medals, diplomas, points and prizes.”

Ujah said in a statement that he accepted the decision with “sadness” but claimed he had “unknowingly consumed a contaminated supplement”.

The 27-year-old apologised to his teammates, Zharnel Hughes, Nethaneel Mitchell-Blake and Richard Kilty.

“I would like to make it clear that I unknowingly consumed a contaminated supplement and this was the reason why an anti-doping rule violation occurred at the Tokyo Olympic Games,” Ujah said in a statement.

“I would like to apologise to my teammates, their families and support teams for the impact which this has had on them.

“I’m sorry that this situation has cost my teammates the medals they worked so hard and so long for, and which they richly deserved. That is something I will regret for the rest of my life.”