Norfolk Police have launched a murder inquiry after a man was found dead at the home of former boxing world champion Herbie Hide.
Officers were called to the private party in Bawburgh, Norwich at 12.07am today, Norfolk Constabulary said.
The victim, in his 20s, was pronounced dead at the scene, in Long Lane, at 12.44am.
A police spokesman said: "Mr Hide and his family have relocated as police carry out investigations at the scene."
Police said there were around 100 people at the party.
Detective Superintendent Julian Gregory, from the joint Norfolk and Suffolk Major Investigation Team, said: "We are in the early stages of our investigation and working to establish the sequence of events which led to this man's death.
"We are also in the process of confirming the victim's identity and police family liaison officers have been assigned to work with next-of-kin.
"A large number of people are known to have been present at the property at the time and while we continue our efforts to identify and speak to all party goers, I would urge anyone who left the scene before speaking to police to contact Norfolk Constabulary as soon as possible on 101."
Police said officers will be providing high visibility reassurance patrols in the area today and a Home Office post-mortem examination is expected to take place this afternoon.
Anyone who has information about the incident is urged to contact police on 101 or call Crimestoppers anonymously on 0800 555111.