LONDON (REUTERS) - Britain have been stripped of their Olympic silver medal in the men's 4x100m relay in Tokyo last August after the Court of Arbitration for Sport (CAS) upheld Chijindu Ujah's anti-doping violation on Friday (Feb 18).
The 27-year-old has been provisionally suspended since Ostarine and S-23 - both substances prohibited by world anti-doping organisation Wada - were detected in his A and B samples following the final.
In a statement, CAS said its anti-doping division had found that Ujah had committed an anti-doping rule violation and that his team's result from the 4x100m relay on Aug 6 had been disqualified.
Ujah and his relay teammates Zharnel Hughes, Richard Kilty and Nethaneel Mitchell-Blake finished narrowly second behind Italy. Canada will now be upgraded to silver with China moving into the bronze-medal position.
In a statement, CAS acknowledged that Ujah had not challenged the decision in his written submissions to the hearing and that he claimed he had "not knowingly or intentionally doped".
He said he had been left "devastated" by his violation.
"I accept the decision issued by the Court of Arbitration for Sport today with sadness," Ujah said in a statement issued by UK Athletics (UKA) on Friday.
"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.
"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."
A UKA spokesman added: "UKA continue to be in regular communication with the athletes concerned but will not be making public comment on the case until after the World Athletics/AIU process which will follow on from this CAS outcome."
Britain suffered a disappointing performance in track and field in Tokyo, failing to win a gold for the first time since the Atlanta Games in 1996.
Ujah was eliminated in the semi-finals of the individual 100m.
He will now have to wait for the Athletics Integrity Unit to determine the length of any ban, which could be as long as four years.