Emergency services were called to Anambah Road at Rutherford, 8km north-east of Maitland, shortly after 9pm (Saturday 7 November 2020), after a utility hit a guard rail.
A 29-year-old man travelling in the front passenger seat was thrown from the vehicle and died at the scene.
Officers from Port Stephens-Hunter Police District attended the scene and commenced inquiries.
The 33-year-old male driver was arrested and taken to John Hunter Hospital for mandatory testing, before being taken to Maitland Police Station where he is assisting investigators.
Officers from the Crash Investigation Unit (CIU) are investigating and are appealing for anyone with information, or dashcam vision, to contact them via Crime Stoppers on 1800 333 000.