Botswana’s Nijel Amos has been banned for three years after the 2012 Olympic 800 metres silver medallist tested positive for a banned metabolite.

The Athletics Integrity Unit said on Wednesday the ban would come into effect from July 12, 2022, the date of his provisional suspension, and end on July 11 2025.

“His results on and since June 4, 2022 have been disqualified,” the statement added.

The drug found in the 29-year-old’s system, GW1516, modifies how the body metabolises fat, and the World Anti-Doping Agency has said it poses a health risk to athletes.

Amos’s silver at the London Games was Botswana’s first Olympic medal.

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The African nation won bronze in the 4x400m relay at the Tokyo Games in 2021.

Amos equalled the third-fastest time in 800m history at the age of 18 when he won the silver medal behind world record-breaking David Rudisha of Kenya at the 2012 London Games.

His silver medal is not affected by the doping ruling.

The 29-year-old Amos is a three-time Olympian who has won titles at the African Championships and Commonwealth Games.

His time of 1 minute, 41.73 seconds from the 2012 Olympics remains the world junior record.

The AIU ruling said Amos initially asked for tests to be run on a supplement he had been taking before the positive test.

No traces of GW1516 were found in either the bottle he had used or another, unopened bottle of the same supplement, the AIU said, adding Amos then signed a form admitting to the doping charges.

GW1516 was developed to help build endurance and burn fat but was found to cause cancer during tests on rodents.

Anti-doping organisations have warned athletes not to use it on safety grounds.

It has been found in doping cases in various sports and also led to a ban for another 2012 Olympic medallist, Russian racewalker Elena Lashmanova.

-with AP