United States sprinter Sha’carri Richardson had a sharp response to the decision to allow Russian figure skater Kamila Valieva to compete at the Beijing Olympics despite testing positive for a banned substance, suggesting a racial double standard was at play. Richardson served a one-month suspension and was not allowed to compete at the Tokyo Olympics after testing positive for THC, the main psychoactive component of marijuana. At the time, Richardson said she had used marijuana to help her grieve the death of her mother. In a series of tweets published Monday, Richardson asked, “Can we get a solid answer on the difference of her situation and mines [sic]?”

“It’s all in the skin,” Richardson said. “My mother died and I can’t run and was also favored to place top 3. The only difference I see is I’m a black young lady.”

The “favored to place top three” line is a reference to the International Olympic Committee decision for no medal ceremony if Valieva medals in the individual competition.

“The IOC will, in consultation with the athletes and [National Olympic Committees] concerned, organize dignified medal ceremonies once the case of Ms. Valieva has been concluded,” IOC Director of Communications said Monday.

Richardson noted some differences between her case and Valieva’s in her tweets, as well. While trimetazidine, the substance Valieva tested positive for, is banned by the World Anti-Doping Agency (WADA) because it can help endurance and increase blood flow efficiency, Richardson Tweeted “THC definitely is not a performance [enhancer].” She also noted differences in the amount of time between reporting and suspension in each case, as well as the decision to allow Valieva to compete despite an ongoing investigation.

“Failed in December and the world just now know [sic] however my [results were] posted within a week and my name & talent was slaughtered to the people,” Richardson said. “Not one BLACK athlete has been about to compete with a case going on, I don’t care what they say!!!”

There are other differences in play, as well. For one, Valieva’s case is being handled at the international level, while Richardson’s was handled by the U.S. Anti-Doping Agency (USADA). The other big one is that at 15, Valieva is considered a protected person under the World Anti-Doping Code.

“The panel considered that preventing the athlete to compete at the Olympic Games would cause her irreparable harm in these circumstances,” Court of Arbitration for Sport Director General Matthieu Reeb said.