Residents are being asked to report to the police anyone who has an illegal firearm.
The request follows Northamptonshire Police’s recent weapons amnesty, which saw more than 170 firearms taken off the county’s streets.
Insp Sarah Johnson, who led October’s amnesty, said the aim was to identify people who are still holding weapons illegally in order to help root out gun owners with possible criminal intentions.
She said: “The amnesty was a real success, which saw a lot of people do the right thing to dispose of the weapons in their possession.
“With those people who failed to hand in unregistered weapons during this period, I think it’s reasonable for us to consider their ownership of those items to be questionable.
“So I would encourage anyone who knows people who are still holding unregistered firearms to either contact us or Crimestoppers so we can remove those weapons from the streets and make Northamptonshire a safer place.”
Crimestoppers, which is backing the campaign, is offering up to £1,000 in reward for information which leads to an arrest and charge.
Chairman of Northamptonshire’s Crimestoppers committee James Shepherd Cross said: “We’re proud to back Northamptonshire Police’s campaign to reduce the number of firearms in our community.
“We want the public to know that we take gun crime seriously and that, with their help, we can make Northamptonshire a safer place to live.
“So if people have any information regarding the illegal possession or use of firearms they should not hesitate to contact us.
“Every anonymous call to Crimestoppers is potentially vital to preventing or solving serious crimes, and removing an illegally held firearm may save someone’s life.”
Anyone with any information regarding the illegal possession of firearms can call either Northamptonshire Police on 101 or the independent charity, Crimestoppers, anonymously on 0800 555111 or through an online form.
Information which is passed directly to the police would not qualify for the Crimestoppers reward.