A man has died after he was left seriously injured in a charity white collar boxing match.
He was taking part in the Ultra White Collar Boxing event at Harvey Hadden Sports Village in Nottingham last Saturday.
Nottinghamshire Police said his condition deteriorated since the incident and he has died.
Detective Inspector Chris Berryman said: “Officers attended Harvey Hadden Sports Village on Saturday March 25 with partners including East Midlands Ambulance Service.
“A man was left seriously injured following a boxing match and transported to Queen’s Medical Centre.
“Since the incident, his condition deteriorated and he has sadly passed away.
“Our thoughts are with all of his family and friends at this difficult time.
“We are keeping an open mind and working with the coroner to establish what has happened.”
A spokesperson for Ultra White Collar Boxing said: “Everyone at Ultra White Collar Boxing was deeply saddened to hear of the tragic death of one of our participants, who took part in our Nottingham event on Saturday March 25.
“Our thoughts are very much with his family and friends at this difficult time.
“We are in close contact with his family and continue to offer them all the support we can.
“With investigations now under way by the relevant authorities, it would be inappropriate to comment further at this stage.”
Ultra White Collar Boxing is a partner of Cancer Research UK and the boxing organisation’s website says it has raised more than £25,000,000.
Simon Ledsham, fundraising director at Cancer Research UK, said: “Our heartfelt condolences are with the friends and family of the man who has sadly died following an Ultra White Collar Boxing event in Nottingham.
“Ultra Events – the company which stages Ultra White Collar Boxing events and asks participants to commit to raise funds for Cancer Research UK through sponsorship – is reviewing the circumstances surrounding the incident.
“As with all fundraising, we accept donations from friends and family who sponsor participants and at all times the charity carefully considers the benefit to cancer patients, while fully adhering to guidance from the Charity Commission. We regularly review the arrangement and will continue to do so.
“Ultra White Collar Boxing matches are third party events, organised by Ultra Events Ltd, and the company is solely responsible for all aspects of planning and delivery.”
According to its website, Ultra White Collar Boxing has been running events for 14 years and has organised hundreds of events.
The website says: “Ultra White Collar Boxing (UWCB) is the largest organiser of white collar boxing events in the UK.
“Since the first event in December 2009, over 100,000 people have stepped through the ropes and boxed at one of our events.
“That’s 100,000 people that have become fitter and healthier.
“Boxing gets a tough time from the media.
“Whenever there is an injury there are calls for it to be banned, but statistically, if you look at serious injuries boxing is safer than cycling and rugby.
“We think this is due to excellent safety precautions at events.”
The website lists a summary of guidelines and says: “To ensure the safety of all of our participants, we make sure that we strictly adhere to our rules and regulations.”
It adds: “We feel our events offer a ‘gold standard’ in safety and this has been verified by doctors, neurosurgeons and many other professional bodies that have reviewed our practices.”