A murder investigation has been launched after a man in his 30s died at an all-night party.

Two men have been arrested on suspicion of murder after the man collapsed on the sofa at a flat in Halland Road, Moulsecoomb, Brighton, fell asleep and could not be woken.

The men dialled 999 at about noon yesterday. Paramedics called in police when they found the man had died.

Detectives were carrying out house-to-house inquires on the estate today.

The dead man is believed to have been a guest at a party in the two-storey council flat which attracted complaints from neighbours.

Police and paramedics were first called to the flat at about 1am yesterday after a window was broken.

The man who later died is thought to have been heard arguing with police and ambulance crews and refusing to go to hospital.

Bob Allen, 40, who lives a few doors away, said: "There was a lot of noise at the party.

"It got really bad at about 1am when I heard a window smash and then police and paramedics arrived.

"Police went into the house and tried to calm things down. I heard the man who was injured shouting and swearing at the ambulance crew.

"I heard a paramedic say: 'He won't let us take him. He has only got a broken nose.'

"I have never seen the man before. The party continued with loud music throughout the early hours of Sunday morning.

"The man who died is one of a number of people who come and go from the flat."

A police spokeswoman said: "The death is being treated as suspicious and two people have been arrested on suspicion of murder."