US sprinter Sha’Carri Richardson could miss Tokyo Olympics after positive cannabis test

The American sprinter Sha’Carri Richardson could miss competing in the 100 metres at the Olympics in Tokyo after testing positive for cannabis.

She had been regarded as a gold medal favourite, having run the sixth fastest time in history during trials.

The Anti-Doping Agency said she had accepted a suspension of one month starting from the end of June. She may still be able to compete in the 4×100 metre race.

We spoke to Michele Verroken, formerly the director of ethics and anti-doping at UK Sport. She is now the director of the consultancy firm Sporting Integrity.