Olympic medalist Amos suspended for doping

Monaco: Nijel Amos, an Olympic silver medalist in the men's 800 meters, has been suspended ahead of the world championships after testing positive for a rare banned substance.

The Athletics Integrity Unit said Tuesday that the 28-year-old Amos gave a sample on June 4 which was found to contain GW1516, an experimental drug which can modify the body's metabolism but has been considered too dangerous for human use.

Amos had been set to race the 800 heats of the world championships in Eugene, Oregon, on July 20. He won silver at the 2012 Olympics, becoming the first-ever medalist for Botswana.