A machete-wielding man has been filmed fleeing an Upper Hutt dairy after its fog cannon was activated.

Merton Mini Mart owner Narendrakumar Patel said a man with a black shirt wrapped around his face came into the store about 5.30pm on Monday.

Patel’s wife was looking after the shop at the time and noticed the man was loitering in the aisles, so she got a bit suspicious, he said.

“All of a sudden he took a sword type of thing from his pants, and my wife was a little bit threatened, and we have a panic alarm which she pressed.”

Patel said the alarm set off a high-pitched siren noise which sent the man on his way.

“While he was walking out he opened one of the fridge doors close to the exit and grabbed a bottle of Fanta and ran off.”

His wife then called Patel to tell him what had happened and they rang 111.

But just a few minutes later the man returned, so Patel’s wife activated the dairy’s fog cannon, which sent a stream of smoke through the store.

Patel said it was enough to force the man out, but he again grabbed something from the mini-mart before leaving.

“This time he took a packet of chippies with him and stood outside,” Patel said.

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“By that time, I was on the phone with police on 111 and we managed to get the police within 10 minutes or so.”

A police spokesperson confirmed a 30-year-old man was arrested nearby about 5.40pm.

He is due to appear in Hutt Valley District Court on December 20 and is charged with aggravated robbery.

Asked how his wife was feeling, Patel said: “When he pulled that sword ... she got a little bit frightened and now she’s okay, but it is terrifying.”

Patel said it’s the first time the fog cannon has had to be used for a live incident since it was installed about four years ago.

Last month Prime Minister Jacinda Ardern announced new measures to combat retail crime, including a fog cannon subsidy scheme open to all small shops and dairies in New Zealand.

“Funding of $4000 will be available for each shop who will be able to have the fog cannon installed through an approved supplier, meaning they can access them directly without an onerous process,” she said.

This will add to the 1000 fog cannons already installed since the fog cannon fund was set up in 2017.

The announcement was made on the same day many dairies across the country shut their doors for two hours to protest at what were considered insufficient Government measures to address crime following the alleged murder of Sandringham shopkeeper Janak Patel.