A teenage girl has died in hospital after being attacked by a dog at a home in the NSW Hunter Valley last week.

Emergency services were called to the house in Singleton about 11:30am on September 4, where they found 17-year-old girl suffering critical injuries to her head, neck and body.

She was treated at the scene by NSW Ambulance paramedics before being flown to John Hunter Hospital in a critical condition.

The entryway to a hospital

The teen was flown to John Hunter Hospital in Newcastle after the attack. (ABC Newcastle: Bindi Bryce)

Police were told the girl was at a friend’s home when she was mauled by a 10-year-old, mixed-breed dog that lived there.

It is understood passers-by intervened, pulling the dog off the girl while calling for help. 

The dog — a mix of boxer, bull Arab and Irish wolfhound — was destroyed with the consent of the owner.

It is understood the animal was in a fenced yard at the time of the attack. 

On Monday, police were notified that the 17-year-old girl, who was a student at Singleton High School, had died in hospital.

Police are investigating and a report will be prepared for the coroner.