A man in his 20s has been arrested on suspicion of murder following the death of another man.
Emergency services were called to Euston Road, Great Yarmouth, to attend to a man also in his 20s who had received serious injuries.
He died at the scene and a man was arrested nearby. He is in custody being questioned about the incident.
The address is sealed off and police are interviewing other occupants in the house.
Crime scene investigation officers are carrying out a forensic examination.
Det Chief Inspector Jes Fry said: "We are still in the early stages of the investigation.
"But it has been established that the man in custody was known to the victim and it is believed there was no wider threat to the community.
"The man detained is currently being questioned and this is likely to continue for the rest of the day."