British boxing chiefs said on Wednesday they had "prohibited" a fight between Conor Benn and Chris Eubank Jr after Benn failed a drugs test ahead of the scheduled weekend bout in London.

The catchweight fight was thrown into doubt earlier on Wednesday when it was confirmed Benn had returned an "adverse analytical finding for trace amounts of a fertility drug" only for promoters to insist the contest remained on.

But the British Boxing Board of Control has now said the fight at the O2 arena cannot take place.

Its statement read: "On the evening of 4th October 2022, the board of the British Boxing Board of Control Limited resolved that the contest between Chris Eubank Jr and Conor Benn scheduled to take place on 8th October 2022 is prohibited as it is not in the interests of boxing.

"That was communicated to the boxers and promoters involved on the morning of 5th October 2022."

The contest would be the third bout between the families, after their fathers fought twice in the early 1990s in one of British boxing's greatest rivalries.

Earlier, a joint statement was released by promoters Matchroom and Wasserman Boxing, referring to the doping test.

"We have been made aware that a random anti-doping test for Conor Benn conducted by the Voluntary Anti-Doping Association returned an adverse analytical finding for trace amounts of a fertility drug.

"The B sample has yet to be tested, meaning that no rule violation has been confirmed. Indeed, Mr Benn has not been charged with any rule violation, he is not suspended, and he remains free to fight.

"Mr Benn has since passed a doping control test conducted by the UK Anti-Doping Agency, the anti-doping authority to which the British Board of Boxing Control has delegated its doping control testing for the bout. Mr Benn has passed all doping control tests conducted by UKAD.

"Both fighters have taken medical and legal advice, are aware of all relevant information, and wish to proceed with the bout this Saturday."

Fight week media commitments started on Wednesday with a live workout at a venue in central London getting under way just after 1300 GMT.