Officers were called to a property in Hutton Avenue, Hartlepool, at around 10.20pm on Tuesday, December 31.
The 31-year-old man, named locally as former amateur boxer Mark Denton, was taken to hospital with serious injuries but was sadly pronounced dead.
A 17-year-old has been arrested on suspicion of murder and is being questioned by police.
Residents said there had been a ‘commotion’ at the house and that a party had been taking place.
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