Chris Eubank Jr weighed in at 160.2lbs on his first attempt, then 160.05lbs on his final attempt.
Those 5lbs or 2.67kg will cost him £375k in penalties. Natural welterweight, Benn, came in lighter than expected at 11st 2lbs.
Eubank turned up over an hour late than the scheduled 11am start time today, Friday 25, immediately sparking rumours he was struggling with the weight limit.
Conor Benn and Chris Eubank Jr will still fight in London this Saturday night, April 26, at the Tottenham Hotspur stadium, live on DAZN.
After also being fined £100k by the BBBofC for his antics in February when he violently cracked an egg on Benn's face, he will now drop almost half-a-million pounds before he receives his fight purse.
The weight limit has been the biggest talking point, right from their first scheduled fight date back in 2022.
The Brighton boxer, who mostly operates at super-middleweight, is also limited to a 170lbs rehydration clause.
Now aged 35, Junior is usually known for adding around 14-15lbs on after weigh-ins, coming into the ring closer to light-heavyweight. Limited to only adding 10lbs for this fight will give the reigning IBO world middleweight champion a very different feel to his normal routine, which could be unsettling for him.
Despite this breaking news, Eubank is still the bookies favourite to win as the bigger, stronger, more experienced boxer of the two. 28-year-old Benn still hasn't fought up at world level, like his enemy has.
BBN asked their panel of experts including world champions, promoters, managers, and writers who they think wins and Eubank edged it the very narrow vote at 53%... read more
@AdamCatterall: "Eubank Jr will pay 600k in fines (for cracking an egg on his opponent and being 0.05 over in weight) whilst his opponent provided zero transparency for failing 2 PED tests and received no punishment?!"
@FightDisciples: "2 x failed PED tests, no explanation, Unnecessary rehydration clause, Reduced ring size, Half expecting Eubank to walk with one hand tied behind his back come Saturday. The rematch in October can't come soon enough!"
@EbanieBridges: "Is this true? 500k fine for Chris Eubank Jnr for 0.05lb……. Which is 22grams……. Wild that."
@DarrenReay007: "He missed weight twice. You know the score, you miss weight, you’ve missed weight, doesn’t matter how much and how far."
@RobertMaher_: "Ironic that a 2-time drug cheat in Benn wasn’t fined. And now earns his biggest payday ever. And clean athlete Eubank Jnr is fined $500,000 for missing weight by 0.05lbs. Some business this “sport” is."
@swerv1978: "It’s £375k but yeah still little excessive."