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.

Belgium end US World Cup dreams amid Balogun row
Portugal coach Roberto Martinez confirms departure after loss
Spain eliminate rival Portugal in Cristiano Ronaldo's World Cup exit
Mbappe fires back at Paraguayan senator's racist attack after France victory
UEFA slams FIFA's 'incomprehensible' Balogun decision after Trump call
