Boxer Michael Norgrove has died several days after collapsing in the ring, the British Board of Boxing Control (BBBC) has confirmed.
The 31-year-old Zambian light-middleweight, who was based in London, collapsed on 31 March.
He was treated for bleeding on the brain following the bout against Sedgley's Tom Bowen at The Ring in Blackfriars, south London.
The BBBC described it as a "sad day" for the world of boxing.
General secretary Robert Smith said: "The whole sport feels for his family and we need to let it sink in.
"He was a nice little boxer - but forget boxing for now, it's very sad news indeed."
Mr Norgrove was a sparring partner of Beijing Olympic gold medallist boxer James DeGale.