The International Olympic Committee (IOC) has claimed there is not a “great deal of similarity” between the anti-doping violation cases of figure skater Kamila Valieva and sprinter Sha’Carri Richardson, after the American athlete suggested there was racial bias in her decision.After it was confirmed that 15-year-old Valieva would be eligible to compete in the women’s singles, Richardson posted on Twitter a series of messages criticising the allowance, comparing it to her own case.Richardson, who had been one of the favourites in the women’s 100 metres prior the re-arranged 2020 Olympic Games in Tokyo last year, tested positive for tetrahydrocannabinol - also known as THC - at the United States Olympic Trials.The test indicated the banned substance was in her urine sample on June 19, which she later admitted was from smoking cannabis while mourning the death of her mother, who had died a week before her qualifying race.