Bahrain's 400m world champion Salwa Eid Naser has been provisionally suspended for not making herself available for doping tests, the Athletics Integrity Unit (AIU) said on Friday.
The AIU said that it has booked Naser for "Whereabouts Failures," a charge that if proven right could mean that she won't be able to participate in the Tokyo Olympics next year.
Naser's provisional suspension is the latest among a series of cases against Bahrain's elite squad of female runners. In March, steeplechase Olympic champion Ruth Jebet was banned for four years while Olympic marathon runner-up Eunice Kirwa was banned for the same period last year.
Athletes are required to provide regular updates on their whereabouts to make it possible for anti-doping authorities to carry out surprise testing outside of competition.
A violation occurs when the athlete either did not fill out forms telling the authorities where they could be found, or that they weren't present where they said they would be when testers arrived.
Three violations within 12 months can lead to a suspension if the athlete can't justify why they weren't available for testing.
Naser had won gold at the 2019 Athletics World Championships that were held in Doha in October. She recorded a time of 48.14 seconds, the fastest for a woman since 1985.