The World Boxing Council (WBC) is seeking more information after heavyweight Dillian Whyte reportedly tested positive for a banned substance before his victory against Oscar Rivas.
Whyte beat Rivas on a unanimous points decision at the O2 Arena, making him a mandatory challenger for WBC heavyweight champion Deontay Wilder.
The world body said it had yet to receive any notification from anyone about a positive anti-doping test allegedly yielded by Dillian Whyte in connection with last Saturday's fight.
"The WBC has requested that the British Boxing Board of Control (BBBofC), as the local governing entity that oversaw that fight, formally provide any available information to the WBC."
The BBBofC has made no comment other than saying all anti-doping procedures were carried out for them by UK Anti-Doping (UKAD).
UKAD also had no comment.
Whyte's promoter Eddie Hearn said on Twitter that Whyte and Rivas "were subject to extensive VADA (Voluntary Anti-Doping Association) and UKAD testing for their bout.
"Both fighters were cleared to fight by both bodies and the BBBofC," he added.
Rivas's promoter Yvon Michel said on Twitter he had read a report on the Boxing Scene website with "great stupefaction".
"Up to this moment nobody on the concerned parties have confirmed or denied to us this information," he added.
American Wilder published an expletive-laden tirade on Instagram on Thursday in response to the reports.
Whyte, 31, served a two-year ban between 2012-14 after testing positive for a banned stimulant. The BBC said he risked an eight-year ban for a second offence, if confirmed.
Reuters
