Sha’Carri Richardson, the charismatic runner who took first place in the 100m at the U.S. Olympic trials, tested positive for cannabis, a banned substance, in a drug screening required for the trials, Reuters reported Thursday. It is not clear whether she will face a penalty, but a suspension threatens to take her out of competition at the Tokyo Olympics, scheduled to begin July 23.

Richardson also dropped out of the Diamond League, a major international track and field meet scheduled for July 4, according to Reuters. She was slated to compete in the 200m event at the pre-Olympic event in Stockholm. She competed at the Diamond League’s events held in Gateshead, England in May but did not give a reason for her decision not to participate in Stockholm, tweeting only, “I am human” on Thursday.