A policeman on his way to help other officers involved in a car chase has been killed in a road crash in the New South Wales Hunter Valley.

Police said the 43-year-old sergeant, who worked at the Port Stephens Local Area Command, was driving his patrol car on Lovedale Road at Allandale when it veered off the road and hit a tree late on Saturday night.

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Paramedics were called but the officer died at the scene.

He was the only person in the vehicle.

A police statement said he was on his way to assist other officers who were involved in a pursuit but no other details about the chase have been revealed.

Acting Deputy Commissioner Geoff Mckechnie said the incident would be thoroughly investigated.

“A critical incident investigation has been formed and that’s well underway,” he said.

“Our thoughts are with the sergeant’s family.”

Police have appealed for witnesses to come forward.