MONACO -- Women's 400-meter world champion Salwa Eid Naser has been provisionally suspended for not making herself available for doping tests, the Athletics Integrity Unit said Friday.
Naser, who won gold for Bahrain in one of the biggest upsets of last year's championships, has been charged with whereabouts violations. She could miss next year's Olympics if the case is proven.
Naser was born in Nigeria and moved to Bahrain at the age of 14. She won the world title in October, finishing in 48.14 seconds -- the fastest time by any woman since 1985.
Naser's victory ended a 25-month winning streak for Olympic champion Shaunae Miller-Uibo of the Bahamas, who took silver despite breaking her personal best.
After her win, Naser said her next aim was to target the world record of 47.60 held by Marita Koch of East Germany. It's one of the longest-standing marks in track.
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 means an athlete either did not fill out forms telling authorities where they could be found or weren't 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.
The provisional suspension is the latest in a series of cases against Bahrain's elite squad of female runners originally from African countries. Olympic steeplechase champion Ruth Jebet was banned four years in March for EPO, and Olympic marathon runner-up Eunice Kirwa picked up a four-year ban last year.
A person listed as Naser's agent did not immediately respond to a request for comment.