Anthony Joshua's American debut on June 1 against Jarrell "Big Baby" Miller may be on hold after the latter reportedly tested positive for a performance-enhancing drug.

Dan Rafael of ESPN reported the news Tuesday, citing three sources who said he tested positive for the banned substance GW1516. Miller is scheduled to fight Joshua at New York's Madison Square Garden, but this positive test stems from a random urine test from March 20.

There is a certain level of irony to this development, seeing how it was Miller who accused his British foe of using PEDs leading up to the fight.

Peter Hanson of Sporting News noted Miller implied Joshua couldn't have added as much muscle as he did without using banned substances, although the latter issued quite the response to British media outlets:

"That's a compliment because, if I was, I would not even be able to fit in this shirt. I have been training since I was 18, so that's 11 years. He's looking at my change between 2012 and 2013, but why doesn't he look at the 11 years? Around the [2012 London] Olympics I was around 104 kilograms, then when I turned pro I was around 107 kilogram, so that's around half a stone (approx. 7 pounds). Now I am 115 kilogram, so that's 11 kilograms in 11 years, it averages out. It's just my dedication. Look on my social media, it's my dedication. I wouldn't recommend it to everyone because it's expensive, especially the food I drink and the lifestyle and training."

If the fight does still take place, Joshua will put his IBF, WBA super and WBO titles on the line against the challenger.