An Olympic weightlifting bronze medallist has been stripped of his medal after being found to have rat poison in his system.

The lifter from Kyrgyzstan in Central Asia, Izzat Artykov, has become the first Rio medallist to test positive for a banned substance, the Court of Arbitration for Sport said.

The substance detected was strychnine, the active material in poison used to kill rodents.

But strychnine, a toxic alkaloid, is also known as a substance than an enhance athletic performance.

When ingested strychnine causes muscular convulsions before death through asphyxia, but in small doses it can boost athletic performance and serve as a recreational stimulant.

Strychnine, was also reportedly used widely by cyclists in the early days of the Tour de France, is defined as a stimulant in the World Anti-Doping Agency’s list of banned substances.