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.

THC has not been associated as performance-enhancing.

Richardson was given a one-month ban by the United States Anti-Doping Agency (USADA) starting from her last competition date, June 28, meaning she would be eligible to compete again on July 27.

Although this ineligibility period did not cover the women's 100m at Tokyo 2020, Richardson's results at the Trials were declared null and void, meaning she did not finish in the top three in the final - a requirement for US selectors.

Valieva's anti-doping violation case is ongoing, with the minor, who is competing for the Russian Olympic Committee (ROC), being cleared to compete in the women's singles competition after the Court of Arbitration for Sport (CAS) kept her provisional suspension lifted despite appeals.

The International Testing Agency, on behalf of the IOC, the World Anti-Doping Agency (WADA) and the International Skating Union all filed appeals to reinstate the suspension which would have banned Valieva from participating in women's events at Beijing 2022. 

"Can we get a solid answer on the difference of her situation and mines?" said Richardson on Twitter.  

"My mother died and I can't run and was also favoured to place top three. 

"The only difference I see is I'm a black young lady."

The sprinter added further posts about the ongoing controversy, reiterating her opinion that it was related to racial bias.

"It's all in the skin," she followed.

"THC is definitely not a performance enhance!!!

"Failed in December and the world just now know however my result was posted within a week and my name and talent was slaughtered to the people."

The 21-year-old was referring to Valieva's positive test for banned substance trimetazidine, a medicine usually used to prevent angina attacks and help blood flow to the heart.

The figure skater claimed her positive sample came from contamination from her grandfather's heart medication.

Valieva's positive sample was on December 25 during the Russian Figure Skating Championships in Saint Petersburg.

Reasons over why the sample from the WADA-accredited Stockholm laboratory took until February 7 in Russia - February 8 in Beijing due to time zone differences - for parties to be notified, are still unclear.

Richardson could have been selected for the women's 4x100m relay, but was not chosen, meaning she missed the Olympics.

In another tweet, the sprinter alleged that no black athlete had been given the privilege to compete while a case was ongoing.

Her team-mate Brianna McNeal was, however, able to compete under protest at the US Olympic Trials while being investigated for "tampering with the anti-doping testing process".

She was later banned for five years by the Athletics Integrity Unit for the offence and fourth-placed Gabbi Cunningham took her spot on the Olympic team in the women's 100m hurdles.

Barrister and general counsel Emir Crowne noted that he secured "interim relief" for Jamaican discus thrower Traves Smikle, who is also black, in his CAS case back in 2015.

Smikle served a two-year ban for testing positive for banned substance and diuretic hydrochlorothiazide.

He later won silver at the 2019 Pan American Games and 2018 Commonwealth Games in the event.

When asked a question in today's press briefing about Richardson's comments, IOC spokesperson Mark Adams said they were dissimilar.

"Obviously every single case is very different, this one [Valieva's] hasn't even reached the end of its case yet," said Adams.

"In terms of Ms. Richardson's case, she tested positive on June 19 quite a way ahead of the Games.

"Her results came in early order for USADA to deal with the case on time before the Games.

"Ms. Richardson accepted a one-month period of ineligibility which began on June 28 so I'd suggest there isn't a great deal of similarity between the two cases."

Because of Richardson's admission, there was no significant period of provisional suspension before her one-month ban was implemented.

A provisional suspension is typically in place when a doping investigation is ongoing prior to a verdict, however, the provisional suspension put in place by the Russian Anti-Doping Agency was lifted the day after when protested by Valieva.

CAS approved the lifting of the suspension, meaning she is free to compete in the tomorrow's women's free skating, which will determine the medallists.

If the 15-year-old makes the podium, the Venue and Medal Ceremonies will not take place until the outcome of Valieva's doping case is known.

This is the case for the team event, in which Valieva won both women's events to help the ROC win the gold medal.

As Valieva's team have protested the positive test and are requiring a B sample, her case continues with a period of ineligibility yet to be determined, if at all.