Michael Hill last night demonstrated its fog cannons at an Auckland mall, one of its newest security measures to deter robbers.

The company has heightened security measures, including using a DNA tracking spray, in stores across New Zealand in response to a spate of robberies and smash and grabs that have targeted its stores.

The cannon could be triggered by a button that staff members wore on a lanyard. It pumped out a non-toxic mist, and last night it filled the New Lynn store in seconds. Throughout the demonstration, visibility was reduced to a distance of about 30cm.

Michael Hill chief financial officer Andrew Lowe said the cannons were mainly being installed in Auckland stores because most robberies "have been Auckland focused".

Fog cannons have already been installed in a number of stores, Lowe said. The installation of a fog cannon costs up to $6000 but the cost varied depending on the store.

Michael Hill demonstrated how its fog cannons work at its Lynn Mall store, one of a raft of new security measures following a recent spate of robberies across the city. Photo / Carson Bluck

He said he had never seen a fog cannon operate in person, but had watched them activate on video.

"I've seen that we've had a couple activate, one in Vulcan Lane and one of our other stores, but they were for incidents in the middle of the night, not when we had people around and also in a closed environment. We've got grills here in the stores in LynnMall."

Michael Hill has funded the extra security measures itself, but a $6 million Small Retailer Crime Prevention Fund was set up earlier this year to help vulnerable, small businesses prevent ram raids at their stores.

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"We have static security guards in every store every day in Auckland, and that comes at a cost. Strengthening doors, installing fog cannons, that's something we're funding to protect our team and to protect the public," Lowe said.

The purpose of the cannons was to push offenders out of the stores in the event of a robbery, Lowe said, rather than as a deterrent itself. The demonstration was also a trial for what impact the fog had on the wider mall.

Michael Hill chairman Rob Fyfe and New Zealand national retail manager Michael Bell at Takapuna branch, following ram raids at several of the international jeweller's stores. Photo / Supplied

Michael Hill has put in place other "best practice" security measures for retail including, security guards at stores, alarm screamers, more security cameras in and around stores, personal alarms for staff, and extra security at night.

Michael Hill CEO Daniel Bracken said he was "appalled by the attacks we have experienced in our stores".

"It is also disturbing that many of these crimes are being committed by young people. More work needs to be done to understand the underlying societal issue here and look to ways of moving them away from offending.

"In consultation with the New Zealand police we have significantly increased our security and protection protocols to ensure that we are doing everything possible to protect our team members and customers."

Bracken said the company had worked closely with police while rolling out the extra security measures.

"We are thankful to the New Zealand police for their ongoing support and protection and will continue working closely with them on monitoring activity, guidance and advice on the continued protection of our customers and team. The police are making significant progress in successfully apprehending the majority of the offenders involved.

"Michael Hill's key priority will always be the safety and wellbeing of its team
members and customers. The comprehensive and increased protection measures announced today strongly support this objective."

Michael Hill chairman Rob Fyfe said it was unacceptable its staff and customers "now live with this constant threat of attack".

"In attacking our stores, these thieves not only rob us of our products, but they rob our staff and customers of the right to feel safe as they move about our stores and shopping centres. It's unacceptable that our staff and customers are now being regularly confronted with the level of destruction I witnessed when visiting our Takapuna branch.

"It's deeply concerning that these aggravated burglaries and ram raids have become a regular occurrence in our retail shopping precincts in New Zealand. The frequency of these increasingly brazen attacks is reaching a level where we will see some businesses forced to permanently close stores."