Mick Willing, the deputy commissioner of police who oversaw operations in regional NSW, has left the force.
NSW Police on Thursday afternoon confirmed that Mr Willing had left his position.
The unexpected departure comes after reports from media outlets in Sydney that Mr Willing was being considered for - but missed out on - the commissioner job left vacant after Mick Fuller resigned last year.
In a statement on Thursday, Acting Commissioner Karen Webb, who will be sworn in to the top job next week, said Mr Willing served his final day on the force on Wednesday.
"I'd like to take this opportunity to wish Mick and his family all the best for their future endeavours, and thank him for his service," Acting Commissioner Webb said.
Mr Willing was promoted to deputy commissioner last July when he took over as commander of Regional Field Operations, which oversees the work of the three policing regions and their many districts outside the Sydney Metropolitan area.
"Being a country guy mate, I'm very, very privileged to have that responsibility," he told the Newcastle Herald in an interview when he took on the role.
Newcastle City, Lake Macquarie, Port Stephens-Hunter and Hunter Valley police districts are in the NSW Police Northern Region, which stretches from the Hawkesbury River to the Queensland border.
Mr Willing's career spanned more than three decades, during which time he spent six years as the boss of the state's Homicide Squad before moving on to lead the Counter Terrorism and Special Tactics Command.
He began policing in what was then known as the Orana Local Area Command, in his home district in western NSW, before rising to the rank of Detective Inspector - serving as crime manager for 17 years.
Mr Willing spent time in charge of police commands on the Far South Coast and Lake Illawarra, before he was promoted to the rank of Assistant Commissioner.
The Herald contacted Mr Willing for comment on Thursday afternoon.