BEIJING: The doping case of American sprinter Sha'Carri Richardson, who missed the Tokyo Olympics due to a one-month ban, is different from that of Russian figure skater Kamila Valieva at the Beijing Games, the International Olympic Committee said on Wednesday.

The IOC's comments come after Richardson, banned last year for a month for testing positive for cannabis, questioned a decision to allow Valieva to continue competing at the Winter Olympics amid an ongoing doping case.

"Every single case is very different. She (Richardson) tested positive on June 19 (2021), quite a way ahead of the Tokyo Games," IOC spokesman Mark Adams said. The Tokyo Olympics, delayed by a year due to the pandemic, started on July 23.

"Her results came in early order for USADA (U.S. Anti-Doping Agency) to deal with the case on time, before the Games. Ms Richardson accepted a one month period of ineligibility which began on June 28."

"I would suggest that there isn't a great deal of similarity between the two cases," he said.

Richardson was expected to be one of the biggest draws in Tokyo after winning the 100 metres at the U.S. trials. She later said her action to consume cannabis was the result of mourning the death of her mother.

On Monday, however, she demanded an answer from the IOC over Valieva's continued participation at the Games.

The 15-year-old Russian was tested on Dec. 25, 2021 but her results were reported only on Feb. 8, a day after she had won team gold in figure skating for the Russian Olympic Committee.

No Olympic medals will be awarded at the women's team event or in the single event if she finishes in the top three of that competition, pending the resolution of her ongoing doping case.

Valieva's automatic provisional suspension on Feb. 8 was lifted by the Russian Anti-Doping Agency on Feb. 9 and an appeal by the IOC, the International Skating Union and the World Anti-Doping Agency to have it reinstated was rejected by the Court of Arbitration for Sport.

"Can we get a solid answer on the difference of (Valieva's) situation and mines?" Richardson wrote on Twitter on Monday. "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."

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