A man has been arrested in Sydney after another man died following an alleged assault during a late-night altercation. Emergency services were called to a unit block on Lister Avenue in Ermington at about 1.15am on Friday after reports of the attack, with paramedics performing CPR before rushing the victim to hospital, where he later died. The incident is being treated as a serious crime and remains under active investigation by New South Wales Police.

Officers found the victim, believed to be in his 40s, seriously injured at the scene before he was taken to Westmead Hospital in a critical condition. He is yet to be formally identified. A 30-year-old man was arrested at the scene and taken to Gladesville Police Station, where he remains for questioning as inquiries continue. A crime scene has been established, and police are appealing for anyone with information to contact Crime Stoppers.