High-powered sniper rifles designed to fire armour-piercing rounds up to 2km can be purchased in New Zealand with the most basic firearms licence.
Military forces around the world use semi-automatic models of the .50 calibre rifles, but bolt action versions are sold by gun stores here for less than $10,000.
Videos posted on social media online show armour-piercing incendiary rounds punching through vehicle engines and concrete blocks.
Anyone who wants to purchase a restricted weapon, such as a military style semi-automatic, must give a "good reason" to police for the importation to be approved.
But the .50 calibre rifles and armour piercing rounds are available to anyone in New Zealand with a standard A-category licence.
Someone as young as 16 can get an A-category licence.
If they had "sinister designs", former police Assistant Commissioner Nicky Perry said a gunman could hit a person or vehicle from up to 2km.
"It's accurate. The armour-piercing round can go through about an inch of armour plate," Perry told MPs at the Select Committee inquiry into firearms less than two years ago.
"So those army LAVs, for example, those rounds would be punching straight through them."
The .50 calibre rifles did not feature in the final Select Committee report in 2017.
Most of the recommendations, including a closer look at a new semi-automatic licence category, were rejected by then Police Minister Paula Bennett.
But following the deaths of 50 people in the terrorist attack in Christchurch, Prime Minister Jacinda Ardern said our gun laws will change.
"As soon as New Zealanders hear this person was legally able to acquire those weapons and carry out this event, that will raise enormous questions with our gun laws," Ardern said.
"And that is why we will respond swiftly."
Most of the focus has been on a loophole which means semi-automatic weapons such as the AR-15 can be purchased with a standard A-category licence.
But these weapons can be converted into military style semi automatic (MSSA) by simply inserting a high-capacity magazine.
Anyone - with or without a firearms licence - can purchase high-capacity magazines which can hold up to 100 rounds.
This gap in the legislation was exploited by the alleged shooter in Christchurch.
Following the Prime Minister's comments on Saturday, the Police Association - which has long advocated for tighter gun control - said there was no place in the upcoming debate for the radical gun lobby.
"The bitter irony with this alleged perpetrator in Christchurch is he would not have been able to buy the weapons he had in his home country of Australia," said Chris Cahill, president of the Police Association.
"Immediately after the Port Arthur massacre in 1996 the then Prime Minister John Howard acted swiftly to ban semi-automatic weapons and Australians were with him."
Speaking to the Herald today, Cahill said "middle New Zealand" would be shocked that .50 calibre weapons, designed to destroy vehicles, are readily available.
"I think most people would ask why you'd need a gun like that. It shows how antiquated our gun laws are. It also shows there are more issues than just MSSA," said Cahill.
"We need urgent action. But we also need a more in-depth look at some of the other issues and loopholes."
The Herald also revealed a November 2018 briefing to Police Minister Stuart Nash which highlighted "gaps" in the legislation which meant it was "difficult or unable" to enforce the law.
The briefing was in response to a query from Nash as to whether police were putting enough resources into enforcement of current obligations of licence holders.
"It is not solely a question of resourcing, though the gap between revenue from the licensing and permitting regime and the costs of managing that regime is large and growing," the report said.
"Beyond resource limitations, there are gaps in the legislative system that make the system difficult or unable to be enforced."
As well as pointing out the lack of regulation on MSSA parts, such as high-capacity magazines, police noted several other loopholes.
While it is an offence to supply "A category" firearms to anyone without a licence, there is no requirement on non-dealers (the majority of firearms licence holders) to maintain a record of the person to whom they sold the firearm.
There is also no system for dealers or non-dealers to confirm the licence status.
"Those supplying firearms may not necessarily recognise a fraudulent licence or may be prepared to accept the advice of the purchaser rather than insist of viewing the licence."
Likewise, there is no requirement to record sales of ammunition.
And while A category licence holders have to meet the safety storage conditions, there is no provision for police to inspect the storage to ensure the conditions are being met.
"No risk management system is perfect but, should an 'A' category licence holder choose not to comply with the intent of the [Arms] Act the probability of this being discovered is negligible.
"With 250,000 firearms licence holders, even marginal levels of non-compliance can lead to a significant number of firearms ending up in the wrong hands."