Bahrain's 400m world champion Salwa Eid Naser was provisionally suspended for registering four 'whereabouts failures', the Athletics Integrity Unit (AIU) said on Sunday.
"The investigation into Ms Naser's three whereabouts failures in 2019 was ongoing at the time of the Doha World Championships and she was not provisionally suspended at that time," the AIU said in a statement on their Twitter handle.
"Following conclusion of the investigation and a fourth whereabouts failure in January 2020, a Notice of Charge was issued and Ms Naser subject to an immediate provisional suspension.
"The disciplinary process is on-going and the AIU will not comment further on the matter at this stage," the statement said.
In an Instagram video, Naser had said she had 'only missed three drug tests' and that the missed tests came before the September event in Doha.
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.
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.
( With inputs from IANS )