A significant number of people are withholding relevant medical information when applying to own a gun.
Those are the findings of a pilot scheme in Durham which is being rolled out across the country.
Police put in the voluntary checks in the wake of the Horden shootings in which three women lost their lives.
Watch Frances Read's report:
"The UK has some of the toughest gun laws in the world. The authority to possess firearms is only granted in limited circumstances and is subject to stringent control. We are strengthening guidance on firearms licensing as it is essential police are able to access all information that may be relevant to an applicant’s suitability to possess a firearm or shotgun, including information held by GPs.