Dillian Whyte's status as the WBC interim world heavyweight champion is in jeopardy.
He's been provisionally suspended by the organisation after testing positive for a banned substance.
The 31-year-old Englishman failed a drug test three days before he beat Oscar Rivas earlier this month.
Whyte has occupied the top spot in the division behind Deontay Wilder for more than a year and a half.