Despite the failed test the bout still went ahead, with Whyte winning by unanimous decision.
The Brixton-born fighter has been pushing for a fight with Deontay Wilder for some time.
Following his win against Rivas, Whyte was made mandatory challenger for the WBC belt and could fight Wilder in the near future.
However, if the news of his failed drugs test is true, he won't get the chance to fight for the world belt.
- Whyte reportedly fails drugs test
- Maxim Dadashev's trainer begged him to stop fighting
- Maxim Dadashev passes away
Wilder has now responded to the news on Instagram and he has not held back.
"Now here you have a fighter that has been recently reported of taking PED’s (Performance Enhancements Drugs)," he wrote.
"In fact it was said he had over more than 1 substance in his body.
"This fighter has been caught before using PED’s so this is his second attempt.
"This s*** has to stop... The bleeding has to stop somewhere.
"We just had a fighter to fucking die in the ring because of taking too many blow to the head and you have idiots like @dillianwhyte want to CHEAT just to come up in his career because he’s not good enough to do it alone.
"Oscar Rivas was his opponent that Dillian fought recently on drug in which Oscar dropped this drug user and almost beat him, so Mr Whyte all that and the s*** half way worked you still got put on your ass!!! I’d get my money back!!!
"He’s been claiming to want to fight me but the question is if you're doping with a non Champion just imagine what you will try to use if you had the chance to fight me? (Overdose)
"Him and his promoter #EddieHearn gave the @wbcboxing & @wbcmoro hell while all alone this MF has been cheating smh then have the audacity to try and snitch on his countrymen #Aj and accuse him of doing drugs when he himself is doing it as well.
"On top of that his promoter tried his best to cover this up before Whyte’s recent fight. Somebody come and look at this s***...
"I get criticised about saying things like “Ima kill you” and mean it but without any substance whatsoever in my body but here you have so many Fighters like the likes of Dillian Whyte that flood their body with PED’s just to advance to the next level, while committing an attempt to murder but want to speak against PED users smh, GTFOH.
"Lmao... Boxing’s a place where you can hate it but love it all at the same damn time.
This ***** is definitely the Donkey Of The Year!!!"
Strong words from Wilder.News Now - Sport News