Kyrgyzstan weightlifter Izzat Artykov has become the first Rio medallist to test positive for a banned substance and has been stripped of his bronze.
Artykov finished third in the men's -69kg weightlifting competition.
The Court of Arbitration for Sport said the 22-year-old's "medal is forfeited" and "he is excluded from the Games" after testing positive for strychnine.
The bronze medal will be reallocated by the weightlifting federation and the International Olympic Committee.
Colombian Luis Javier Mosquera Lozano would be the weightlifter to move into the bronze medal position, having finished fourth.
Meanwhile, Moldovan canoeist Serghei Tarnovschi has been provisionally suspended for failing a drug test.
The 19-year-old was set to compete in the 1,000m C2 event on Friday with his older brother, Oleg.
However, the International Canoe Federation said Tarnovschi - who won C1 1,000m bronze on Thursday - will "no longer be eligible".
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