A man has been arrested after another man died after allegedly being bashed to death by another man in a late night altercation.

Emergency services were called to a unit block on Lister Avenue, Ermington, at about 1.15am on Friday following reports of an assault.

Police found a man, believed to be in his 40s, seriously injured at the scene.

Paramedics performed CPR on the man before he was rushed to Westmead Hospital in a critical condition, where he died a short time later.

The man is yet to be formally identified.

A 30-year-old man was arrested at the scene and taken to Gladesville Police Station, where inquiries are continuing.

No charges have been laid.

A crime scene has been established and investigations have commenced into the circumstances of the incident.

A man has died following an alleged altercation at a unit block in Ermington

A man, 30, was arrested at the scene

Inquiries are ongoing.

Anyone with information is urged to contact Crime Stoppers.