More than 600 firearms were seized by Auckland police officers, in less than a year.

In the year from December 2018, officers attended 566 firearms incidents, with a police firearm discharged 78 times.

As a result, 23 people were injured and seven died.

Police Association president Chris Cahill says these figures demonstrate why firearms are needed by officers so often.

He told Mike Hosking the longer nothing changes, the closer we get to a permanent armed police force.

"We need to get handle on the firearms on New Zealand and see how they are all ending up in the hands of gangs in the first place."

He says the rising figures is why New Zealand needs a national gun register would help officers understand where and how many firearms are in the country.

"There is so many firearms out there in the hands of criminals, we've got to stop them getting to them. We know many of them are stolen from licensed firearms owners."

The data's been collected as part of the Gun Safe initiative, which was designed to keep track of the number of guns in circulation.