Police are investigating after a man was found fatally stabbed in the Lake Macquarie area of NSW.

Shortly after 4am on Sunday, emergency services were called to Argenton, 16km west of Newcastle, following reports of an assault.

Officers attached to Lake Macquarie Police District arrived to find a man aged in his 30s had been stabbed.

He was treated at the scene by NSW Ambulance paramedics, however he died at the scene.

He is yet to be formally identified.

A crime scene has been established, with detectives commencing an investigation.

The area is expected to remain a crime scene for a considerable amount of time and motorists are urged to avoid the area.

Anyone with information is urged to contact Lake Macquarie or Crime Stoppers.