The man, believed to be a 21-year-old from Queensland, was killed when his car was involved in a crash with three semi-trailers and another vehicle at around 11pm.

The Holden Commodore sedan the man was travelling in was ripped in half and wedged beneath one of the semis as a result of the crash.

The Port Macquarie Crash Investigation Unit reported his injuries were too severe to allow identification to take place immediately. DNA testing would take some time, the unit reported.

Two people in the other car escaped injury, while one of the truck drivers was taken by ambulance to Macksville hospital for treatment due to shock.

The accident saw heavy traffic banked up overnight, while lighter vehicles were diverted around Upper Warrell Creek Road throughout the night and the morning.

Trucks stretched on the highway for many kilometres in both directions before full flow was restored. Drivers were also diverted around the New England Highway.

The Port Macquarie Crash Investigation Unit is looking into the causes of the crash, and has appealed for witnesses to contact police via Crime Stoppers on 1800 333 000.

A report will be prepared by police for the NSW Coroner.