Marina Arzamasova, the former 800 metres world champion of Belarus has been provisionally suspended after testing positive for a banned substance, the Athletics Integrity Unit (AIU) said on Tuesday.

“The AIU confirms a provisional suspension against Belarusian middle-distance runner Marina Arzamasova for a violation of the IAAF Anti-Doping Rules,” it said in a tweet.

The 31-year-old, won gold in the 800 metres at the 2015 World Championships in Beijing, has tested positive for LGD-4033, a substance similar to anabolic steroids that is prohibited by the World Anti-Doping Agency.