A woman has been arrested near Nyngan during a state-wide police operation on gun compliance.

A police spokesperson said officers from Proactive Crime Team Central North acted on information from the public on Friday 17 October when they stopped a vehicle in the village of Hermidale along the Barrier Highway at about 3:45pm.

A search allegedly uncovered a double barrel shotgun and ammunition.

"The 44-year-old female driver was arrested and taken to Nyngan Police Station," the police spokesperson said.

She was charged with three offences related to unauthorised possession and unsafe storage.

The Victorian woman was granted conditional bail to appear at Nyngan Local Court on Monday 27 October.

The arrest was part of a week-long operation by the National Illicit Firearms Working Group (formerly Operation Athena) between 13-19 October, which involved police from jurisdictions across Australia, federal agencies and New Zealand police.

In NSW Police's Western Region, which covers more than half the state, officers made five arrests and carried out 496 safe storage inspections.

They also made 21 firearms searches: eight on people, nine on premises and four on vehicles. 

“Whilst I am pleased to say that most premises inspected were complying with the legislation, it was disappointing to see some weren’t. One firearm not properly stored is one too many,” said NSW Police Assistant Commissioner Andy Holland, who is the Commander of Western Region.

“If a firearm is stolen due to it not being correctly stored it can result in serious criminal charges against the owner.

“Operations of this nature will be ongoing and if anyone is unsure on what their obligations are I would urge them to consult the Firearms Registry section of the New South Wales Police Force website.”