Dillian Whyte has been provisionally suspended as the mandatory challenger for the WBC world heavyweight title, pending a hearing.
Whyte beat Oscar Rivas at The O2 earlier this month to hand the Colombian his first professional defeat and secure mandatory status to Deontay Wilder's WBC crown, along with the interim belt.
But the Brixton boxer returned an adverse finding, according to the governing body, who stated he can present his case at a hearing to be confirmed soon.
A WBC statement read: "An "A" Sample UKAD collected from Mr. Dillian Whyte in relation with his bout against Oscar Rivas yielded an adverse finding.
"In light of that adverse finding, and pending the outcome of the WBC's own investigation and adjudicatory process, the WBC is provisionally suspending the WBC's recognition of Dillian Whyte as WBC Interim World Heavyweight Champion and Mandatory Challenger of the division.
"The WBC has notified Mr. Whyte and his team of the WBC's suspension, and that it will afford Mr. Whyte the opportunity to present its position to the WBC at an investigative hearing which will take place at a place and time to be announced in the near future.
"Throughout its investigation and hearing, the WBC will afford Mr. Whyte and his team the opportunity to present any available information and materials, and any exculpatory evidence they might deem appropriate."