The British 4x100m relay team has returned its silver medals from the Olympics because of a positive doping sample from sprinter Chijindu Ujah.

The British had finished second behind Italy in Tokyo. Silver now goes to the third-placed Canadians, bronze to China.

Ujah, 28, was found to have traces of the banned substances ostarine and S-23, which promote muscle growth, shortly after the Games last summer.

Ujah had not challenged the anti-doping rule violation, but argued that the positive test was caused by taking a contaminated substance. The International Court of Arbitration for Sport (CAS) ordered the return of the medals.