Russian hammer thrower Kirill Ikonnikov has been temporarily suspended after failing a drug test.
Russia's anti-doping agency RUSADA says Ikonnikov, who finished fifth at the London Olympics, tested positive for an unidentified banned substance on October 8. The test was carried out on the request of the International Association of Athletics Federations.
Ikonnikov has been suspended pending further investigation since November 2.
The 28-year-old Ikonnikov finished sixth at the world championships in Daegu, South Korea, last year.