Sha’Carri Richardson, America’s “fastest woman alive”, may have tampered with her chances of competing in the 100 meters at the Tokyo Olympics later this month after testing positive for cannabis last month.

The 21-year-old Richardson won the 100 meters at the U.S. Olympic Track and Field Trials on June 19, but tested positive at the competition. The test results could invalidate her victory and may have her suspended from the sport for a month or longer. 

Ms Richardson has also been withdrawn from a 200m race in Stockholm scheduled for Sunday.

On Friday, Ms Richardson told NBC that her use of marijuana as a way to cope with the  death of her mother while she was in Oregon for the Olympic trials. 

“I want to take responsibility for my actions,” she said on NBC’s “TODAY” show. “I’m not looking for an excuse.”

The suspension of one month, which started on June 28, means Ms Richardson could run in the 4×100 meter relay if she is listed to represent the U.S. team.

Reuters reports that Jenna Prandini, who came in fourth place at the finals, has already been approached to represent the U.S. in the 100m race in Tokyo.

The World Anti-Doping Agency (WADA) had in January classified marijuana as a ‘Substance of Abuse’, the maximum penalty of which is a four-year ban.

The agency may reconsider the penalties, if the  athlete proves that the drug was used out of competition and was not used for the benefit of sporting performance. In that case, the ban could be reduced to three months with no further investigation into the use. 

The agency set out the period before midnight on the day before a competition in which the athlete is to participate until the end of the competition and the sample collection process as its in-competition window.