About 9.45pm (Saturday, June 11), emergency services were called to Rosemount Road, Denman, south-west of Muswellbrook, following reports a Mitsubishi Colt had lost control and rolled before coming to a stop on the side of the road.

Officers attached to Hunter Valley Police Distract attended along with NSW Ambulance paramedics and Fire and Rescue NSW and assisted the occupants.

One passenger, a 20-year-old man, was treated by paramedics for serious spinal injuries after being ejected from the vehicle. He was airlifted to Royal North Shore Hospital in a serious condition.

Two further passengers, aged 19 and 20, were treated at the scene before being taken to Muswellbrook Hospital in a stable condition.

A crime scene has been established and specialist officers from the Crash Investigation Unit commenced inquiries into the circumstances surrounding the crash.

The driver is yet to be identified and police are conducting inquiries into reports a person had fled prior to their arrival.

As inquiries continue, police are appealing to anyone that may have information or dashcam footage of the incident to come forward.

Anyone with information about this incident is urged to contact Crime Stoppers: 1800 333 000 or https://nsw.crimestoppers.com.au. Information is treated in strict confidence. The public is reminded not to report information via NSW Police social media pages.