The RCMP mistakenly issued licences to 1,356 people granting them authority to purchase "prohibited" class handguns — and then didn't notice the error for 12 years.

During that time, 41 of the people issued those licences in error used them to buy 114 semi-automatic pistols and revolvers.

The RCMP has told those owners that they have to surrender those guns, but 14 of the guns remain in limbo.

"One hundred have been legally dealt with by being transferred, exported, turned in to the police for disposal, physically modified and reclassified as restricted, etc," the RCMP's Tania Vaughn told CBC in a written response.

This Webley 'New Model' .45 revolver is the kind of short-barrel, pre-1946 firearm the 12(7) permit was intended to cover.

"The remaining 14 handguns are either in the hands of firearms businesses or individuals pending a court ruling (revocation hearing), transfer, exportation, etc. The Canadian Firearms Registry has tracked and continues to follow up on these firearms and expects to have all pending dispositions concluded shortly."

The error originally came to light through the research of former RCMP officer Dennis Young of Airdrie, Alberta, who used Access to Information requests to obtain the records. Young is an advocate for Canadian gun owners who says the RCMP isn't coming clean about its own errors.

"It's important for members of Parliament to know that the RCMP and the Department of Public Safety are not reporting these errors when they occur to Parliament. So consequently, when screw-ups like this happen, the parliamentarians don't know, and they're not able to fix problems they're not aware of them in the first place."

'Prohibited' but not illegal

Key to understanding how this happened is the fact that "prohibited" firearms are not completely prohibited.

Canadian law seeks to ban the possession of small and easy-to-conceal handguns: snub-nosed revolvers and short automatics with barrels under 105mm, and all guns chambered for .25 and .32 calibre ammunition. (Those calibres were banned because they were considered typical of the kind of cheap, mass-produced, 'Saturday Night Special' handguns more suited to late-night mayhem than an afternoon at the shooting range.)

But anyone who possessed such a handgun prior to 1998 was allowed to apply to be grandfathered under the law. Those gun owners were issued what are called 12(6) prohibited licenses. Such licences allow them to not only keep the handguns they already own, but also to own, buy or sell new ones in the same category.

A licence designed for heirs

All of the people affected by the RCMP's licensing error, on the other hand, held a category of licence called 12(7), which is intended to allow family members to inherit older weapons such as service pistols, wartime captures and battlefield relics.

The licence can only be granted to someone who is "the child, grandchild, brother, sister or spouse of the lawful owner" to whom the weapon was registered previously. It only applies to handguns manufactured before 1946, and cannot be used to acquire any handguns other than those passed on by the previous owner.

But due to an administrative error, 1,356 12(7) licensees were given 12(6) licences.

Tens of thousands of people are criminals and they don't even know (it). - Former RCMP officer Dennis Young

Many of them may not have noticed the change or understood what it meant. The great majority of those licensees did not take advantage of their new privileges.

But 41 of them did. Some acquired just one or two handguns. One unidentified individual used his new licence to acquire 12 prohibited handguns.

The guns acquired by those 41 owners included more modern models manufactured after 1946. One buyer, for example, had acquired a Dan Wesson. The Dan Wesson firearms company was founded in 1968.

"We have no reason to believe any of these firearms were used in the commission of an offence," the RCMP told CBC News.

Programming error

The RCMP says a "programming error" led to the issuance of the wrong permits in 2003. "The programming error was discovered by the Canadian Firearms Program in February 2015," says an RCMP briefing note prepared for Minister of Public Safety Ralph Goodale in November, 2016.

Early in 2017, the RCMP began sending revocation letters to 12(7) permit holders around the country.

A typical letter reads: "This notice is to inform you that the firearm registration certificates for the firearms indicated below have been revoked, pursuant to Section 71 of the Firearms Act.

"You are required by law to return your firearm registration certificates, without delay, either by mail to the address shown in the top left corner of this page or in person to a peace officer or firearms officer. You have 30 days to deliver your firearms to a peace officer, firearms officer or chief firearms officer or to otherwise lawfully dispose of them."

An internal RCMP memo dating from December 2016 also warns, under the heading Strategic Considerations, that "clients may seek compensation since they acted in good faith."

'Good faith' wasn't good enough, as it turned out. In a written response, the RCMP tells CBC News "there was no compensation offered and the few individuals who sought financial remuneration through reference hearings were denied by judicial authority" — which means that some of the gun owners clearly were left out of pocket.

Young said other errors or sudden changes in the rules can leave people in even worse predicaments.

The RCMP's decision to classify a widely-owned .22-caliber magazine as a "prohibited device" is one such case, said Young.

Briefing notes prepared for Goodale, obtained by CBC News, estimate that there are "tens of thousands" of those magazines in private hands, while the Canadian Shooting Sports Association estimates there are over a million. They were widely sold for many years before the RCMP declared them banned in 2016.

Possession of one of those magazines can lead to a lengthy prison sentence.

"Tens of thousands of people are criminals," said Young, "and they don't even know they're criminals because they don't read the Canada Gazette, or they don't read the bulletins that come out from the RCMP.

"The first time they find out is when they're out hunting, or they're out target shooting, and a police officer stops them and says, 'Oh, you've got a prohibited magazine, sorry but you're under arrest.'

"It's just wrong for any police officer to have the power to have that kind of effect over law-abiding citizens."