NSW Police Commissioner Andrew Scipione paid tribute to Sergeant Richardson outside of Nelson Bay police station on Sunday morning.

"It's a very sad day for the NSW Police Force today," Commissioner Scipione said.

"We have farewelled one of our officers.

"43-year-old Geoffrey Richardson from the Port Stephens Local Area Command was tragically lost to us, killed in a motor vehicle accident just before midnight last night". 

Commissioner Scipione met with Sergeant Richardson's wife and two children on Sunday morning to offer his condolences.

He said police had been at the family home since last night and would remain their to offer their support. 

EARLIER: Police  have rallied around the family of a 43-year-old sergeant who died when his vehicle hit a tree at Allandale on Saturday night.

The officer, from the Port Stephens command, had responded to calls for help in a police pursuit through the Hunter when the crash occurred on Lovedale Road about 11.50pm.

Paramedics attended but the officer, who was the only occupant of the vehicle, died at the scene.

The identity of the sergeant has not yet been released, but Acting Deputy Commissioner Geoff McKechnie told reporters on Sunday morning that the officer was the father of two young children.

"Sadly, overnight, we've lost a fine police officer in the Hunter Region," he said.

"Our thoughts are with the sergeant's family. He is a father of two young children. 

"His wife and family are currently being supported by extended family and colleagues of the officer.

"NSW Police Force will ensure that all available welfare, support and assistance is provided to his colleagues."

Fairfax Media understands Commissioner Andrew Scipione will make a statement later on Sunday.

Details of the police pursuit through the Hunter have not yet come to light.

Newcastle Crash Investigation Unit will assist a critical incident team to investigate the circumstances surrounding the incident.

That investigation will be overseen by the Professional Standards Command.

EARLIER: A police officer has been killed after his car crashed into a tree at Allandale on Saturday night.

The Port Stephens police sergeant, 43, was on his way to assist other police officers who were involved in a pursuit when his car left Lovedale Road about 11.50pm. 

The officer was the only occupant of the vehicle.

He died at the scene, police said.

A police spokesman said a Critical Incident Team assisted by Newcastle Crash Investigation Unit would investigate the circumstances surrounding the incident.

That investigation will be overseen by the Professional Standards Command.

“All information will be provided to the coroner who will determine the cause of death and make any findings about the events leading to the officer’s death,” a police statement said.

“No further details are available at this time.”

Police are appealing for witnesses to come forward. 

Anyone who can assist police should contact Crime Stoppers on 1800 333 000.