Thiago Braz, the Rio Olympic pole vault champion from Brazil, was provisionally suspended over a banned substance.
Braz, 29, was provisionally suspended for the presence or use of ostarine glucuronide or ostarine, according to the Athletics Integrity Unit, which handles doping cases in track and field.
Ostarine, a selective androgen receptor modulator that can help muscle growth, is listed as a banned anabolic agent by the World Anti-Doping Agency.
Provisional suspensions can be issued while awaiting a hearing on charges to determine an official punishment, if any. A positive test for ostarine can mean a ban of up to four years.
Messages were sent to emails listed as contacts for Braz seeking comment.
In 2016, Braz won Brazil’s lone track and field medal of the Rio Games, upsetting world record holder Renaud Lavillenie of France by clearing a personal-best and Olympic record 6.03 meters.
Braz took bronze at the Tokyo Games and fourth at the 2022 World Championships.
His best clearance this year is 5.71 meters, ranking outside the world top 20.
The Associated Press contributed to this report.