An investigation is under way after a 17-year-old amateur boxer died shortly after collapsing in the ring.
Derbyshire Police said they were called to the Post Mill Centre, South Normanton, at 2217 GMT on Friday.
The youth, who is from Ripley, near Derby, was given medical treatment at the bout but was pronounced dead on arrival at Kings Mill Hospital, in Mansfield, Nottinghamshire.
Formal identification has yet to take place and a post-mortem examination is due to be carried out to establish the cause of death.
The centre's website stated that an "amateur open boxing show" was being held at the venue on Friday night, organised by the South Normanton School of Boxing.
The Board of England Boxing said in a statement on Saturday: "It is with great sadness that the Board of England Boxing, the governing body for boxing in England, can confirm that a boxer died last night following a bout at an England Boxing-sanctioned event in Derby.
"We are extremely saddened by this and would like to express our sincere condolences to the family and friends of the person involved in this terrible and shocking incident.
"The Board of England Boxing has set up an investigation to establish the facts of what happened and will provide an update when we know more.
"We are also asking all of the England Boxing coaches, officials and volunteers that were present on the night to co-operate with the police investigation and assist the authorities in any way they can.
"We will be providing support to people that have been affected by this terrible news."
Police have appealed for anyone with footage of the bout to contact the investigations team.
