A 6-year-old boy was killed in a car crash at East Seaham on Sunday afternoon.
Officers from the Metropolitan Crash Investigation Unit are conducting inquires into the single-vehicle crash, which happened along New Line Road shortly before 6pm on July 21.
Police said a 29-year-old woman had been driving a Mazda sedan north on New Line Road at East Seaham when about 5.50pm the car left the road and hit an electricity pole, causing it to roll.
The woman and a 3-year-old girl, who had been seated in the front passenger seat, received facial lacerations and were taken to John Hunter Hospital by ambulance for treatment.
The 6-year-old boy, who had been seated in the back of the car, died at the scene.
Port Stephens SES Unit were on scene to the crash until the early hours of Monday morning assisting police and NSW Ambulance paramedics with lighting.
A crime scene was established, crash investigation unit officers attended and began making inquiries.
The female driver underwent mandatory blood and urine tests at hospital. Inquiries into the crash continue, police said.
The East Seaham fatality is believed to the the fifth road-related death in Port Stephens since the start of the year.
Two men died in separate collisions at Williamtown, on in January and another in May, a woman died in a single-vehicle crash at Tomago in January and two men died on the Pacific Highway at Ferodale in April after the car they were travelling in collided with a truck.
Anyone with information about the crash is urged to contact Crime Stoppers on 1800 333 000 or nsw.crimestoppers.com.au.