Changes to New Zealand's gun laws are expected to be passed this week, but Police Association President Chris Cahill has some concerns about loopholes.
The legislation has drawn both criticism and support since it was announced.
Mr Cahill told TVNZ1's Breakfast today the law change was 20 years overdue, but it is important to get the changes right.
"The Government, and everyone in Parliament really, has made it clear they want to ban military-style semi automatics, but also all assault-style semi automatics," he said. "So we've got to make sure the legislation fits with what that intent is."
If the Government doesn't get it right, there could be additions added to weapons to make them illegal, he said. He used as an example Kali Keys - a product that can change a semi-automatic into a bolt-action rifle, but then can be immediately removed, if desired, to restore the weapon's original function.
"If we don't get these things right around the law, they will sneak in and we won't get the intent," he explained.
Mr Cahill said he believes the vast majority of firearm owners in New Zealand are responsible and wouldn't try to use the loopholes, but he also believes some people would do "whatever they can to get around loopholes".
He said the Government has done a good job drafting the immediate changes, which he hoped would pass this week, but going forward he wants the legislation to stand up against people opposing the law change.
A full review of the Arms Act is needed, including introducing a gun registry and making sure security is appropriate for all firearms, Mr Cahill said.
Some people have criticised the speed in which the Government has acted on the law reform, but Mr Cahill welcomed the change, saying, "as far as I'm concerned, it's been too slow".