Zak Chelli's fight against Lerrone Richards at Alexandra Palace on Sunday afternoon has been postponed after Richards fell in his hotel room and temporarily passed out.
The British boxers were due to fight on the undercard of Sunday's BOXXER: Breakthrough bill, headlined by Adam Azim's bout against Rylan Charlton.
SJam Boxing said on Sunday: "Unfortunately, Lerrone was taken unwell at the hotel last night. Following medical checks and in line with protocols set by the British Boxing Board of Control, it has been decided that Lerrone is unable to compete today.
"It is hugely disappointing given the hard work he has put in throughout his training camp. He will undergo further checks and we hope to look to reschedule his contest with Zak Chelli at a more appropriate time."
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BOXXER CEO & founder Ben Shalom said: "I am deeply disappointed for both fighters. But the welfare of fighters is paramount and unfortunately the contest has been postponed."
Chelli was due to defend his English super-middleweight title against Richards who defeated Carlos Gongora in his last fight.
The fight was on the undercard to Adam Azim's showdown with Rylan Charlton, with the bill also including Mikael Lawal vs Deion Jumah and Sam Gilley vs Sean Robinson.
The television broadcast will start at 3pm on Sky Sports Main Event, Sky Sports Arena and Sky Showcase.
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