Conor Benn's fight against Chris Eubank Jnr on Saturday has been officially postponed after Benn tested positive for a banned substance, co-promoters Matchroom and Wasserman Boxing have announced.
Eddie Hearn and Kalle Sauerland have conceded defeat in their attempts to stage the catchweight meeting at the O2 in defiance of the British Boxing Board of Control (BBBC) declaring it was "prohibited" and "not in the interests of boxing".
The BBBC acted after it was revealed on Wednesday that trace amounts of fertility drug clomiphene, which elevates testosterone levels in men, had shown up in a recent test by the Voluntary Anti-Doping Association (Vada).
"After discussions with various parties, we have taken the decision to formally postpone the bout between Chris Eubank Jnr and Conor Benn," a statement read.
"It is undeniable that the British Boxing Board of Control's decision to withdraw their sanctioning was procedurally flawed and without due process. That remains a legal issue between the promoters and the board which we intend to pursue.
"However, whilst there are legal routes to facilitate the fight taking place as planned, we do not believe that it is in the fighters' interests for those to be pursued at such a late stage, or in the wider interests of the sport.
"As promoters, we take our obligations and duties very seriously, and a full investigation will now need to take place. We will be making no further comment at this time and news for ticket holder refunds will follow."
The bout was billed as a continuation of the Benn vs Eubank feud that saw the rivals' fathers battle it out in two ferocious contests in the early 1990s.
A catchweight of 157lbs was agreed for the sons to continue the family feud into a trilogy fight, meaning Benn would have to move up two weight divisions and Eubank lose three pounds.
What is a catchweight fight?
The bout between Eubank and Benn was due to be a catchweight clash, meaning both men agreed to the weight limit, which was set at 157lb – a touch lighter than middleweight. Eubank Jnr has fought at middleweight and super-middleweight, while Benn usually boxes at welterweight.
Failure to make the contracted weight by either fighter at the weigh-in would have resulted in a £100,000 fine for each pound recorded over the limit, but Eubank Jnr made light of the challenge he faced by posting footage on social media of him eating a burger, fried chicken and cake.
Benn was unimpressed and accused his opponent of lacking respect. "He said he's a man of his word and a disciplined athlete, but do I see him making the weight? No," Benn said.
Eubank Jnr said he relished the challenge of making the weight.
"It's going to be a tough, tough challenge to get down to this weight but it's worth it, it's absolutely worth it, to make a fight like this and be part of a one of a kind event," he said.
When is it?
The fight was scheduled to take place on Saturday October 8 but has now been postponed after Conor Benn's positive drugs test.
Where is it?
It was due to be held at the O2 in London, the venue formally known as the Millennium Dome.
How can I watch Eubank Jnr vs Benn on TV
Dazn had the rights for the fight, which was due to be broadcast on the broadcaster's pay-per-view channel. It would have cost £19.99 on Dazn UK.
How can I buy tickets?
Tickets went on sale on August 13 but managed to sell out. Attendees bought them either by visiting the O2 venue website or by going directly to the AXS site.
Who is fighting on the undercard?
The undercard for Chris Eubank Jnr vs Conor Benn was planned to be:
Mary Romero vs. Ellie Scotney; Women's Junior Featherweights
Galal Yafai vs. Gohan Rodriguez; Flyweight
Harlem Eubank vs. David Martin; Junior Welterweights
Lyndon Arthur vs. Cesar Hernan Reynoso; Light Heavyweights
Felix Cash vs. Connor Coyle; Middleweights
Matty Harris vs. Jiri Surmaj; Heavyweights
Shannon Courtenay vs. Gemma Ruegg; Women's Bantamweights
Chloe Watson vs. Nancy Franco; Women's Flyweights
George Liddard vs. Hrvoje Grcic; Middleweight
Katharina Thanderz vs. Maria Ruiz; Super-lightweight
*Undercard subject to change but correct as of October 5