A rising star in American track and field, Sha'Carri Richardson may have to put aside hopes for Olympic gold in Tokyo this summer.
A source told Reuters that Richardson tested positive for cannabis during trials last month when she sprinted to victory in the 100m race.
A failed drug test would void her results from the meet.
According to another source, Jenna Prandini - who finished fourth - has already been asked to run the 100m for the U.S. in Tokyo.
So far, no official confirmation from Richardson's agent.
But the sprinter earlier tweeted out "I am human".
Cannabis is banned by the World Anti-Doping Agency.
A violation can carry with it a suspension of four years.
But that can be reduced to one month if the athlete cooperates with their country's anti-doping organization to receive treatment.
In theory, that would leave Richardson clear to race in the 4x100m relay on August 6th if she is selected.
Richardson has had her sights set on the 100m Olympic title, aiming to become the first American woman to win it in 25 years.