"Alcohol was being consumed and it is believed that throughout the day and evening there were some disagreements that culminated in a more serious altercation,'' he said.
"It was at this point that the victim is believed to have been fatally injured.''
Police were not saying what his injuries were, and a post mortem examination would be carried out tomorrow to establish the cause of death.
Police had identified a number of people who were at the property and were interviewing them. Anyone who had been there and had not spoken to police should contact them, Mr Kirby said.
They also wanted to know the movements of a red Ford Telstar which was at the house and was believed to have been used to take the man to hospital.
The man would not be named until next of kin had been informed.