Earlier this week, former kickboxing champion Tyrone Spong was pulled from the biggest bout of his boxing career, a shot vs. former world cruiserweight champion Oleksandr Usyk that was scheduled for tonight. The bout's promoter, Eddie Hearn, tweeted a few days ago, "We have been contacted by VADA [the Voluntary Anti-Doping Agency] to inform us that there has been an adverse finding in Tyrone Spong’s test. It has been sent to the State of Illinois commission." Spong was quickly replaced by Chazz Witherspoon in the Usyk fight, which will go ahead tonight in Chicago. This morning, Spong tweeted that he "just received word from VADA that my third and last urine sample taken on Oct 2nd was negative for all prohibited substances. As I’ve said all along, I’m a clean fighter and the previous results were inaccurate or manipulated. Who is responsible for this? It's shameful that I've been robbed of this opportunity... I've been wronged and I'm pissed off." Spong accompanied the social media post with a letter from VADA showing he tested negative with a sample collected on October 2nd..
Note that a negative test does not mean Spong (or any other athlete) never cheated. If the Ocotber 2nd clean test posted by Spong was the B sample of the original positive test, then Spong has a very strong argument for a false positive. But Spong said the negative result came on his "third and last urine sample" in which case there could have been a prohibited substance in his system at the time of the first two tests that had cycled out before the third test. In such a case there could be BOTH cheating by Spong and a negative third test result.