This person was disqualified by a boxing association, the IBA, that the International Olympics Commission no longer works with due to a history of corruption, bribery, etc. Not that the IOC is clean and sparkling, of course. But some of the more eyebrow-raising issues include that the Russian head of the IBA announced a negative test after this boxer beat the top Russian in the tournament in question; the IBA has never said exactly what tests were "failed" (not that it hasn't stopped assumptions and accusations); the proper procedure was not followed at all at the tournament, including, essentially, a Board meeting to discuss what action to take that occurred AFTER the ban had been handed down; and at no other time has either boxer in question had any other negative result on a test. Not to mention, the one mostly in question has boxed in dozens of other tournaments without issue, including the Tokyo Olympics.