Supermarkets giant Foodstuffs has defended its use of facial recognition technology to help combat shoplifters.

Foodstuffs, which includes the New World, Pak'nSave and Four Square brands, has said it uses facial recognition technology in some North Island stores, but won't say which ones.

Pak'nSave supermarkets in Kaitaia, Porirua, Upper Hutt and on West Auckland's Lincoln Rd told the Herald they do not use facial recognition technology.

Hooked up to cameras on a businesses premises, the technology stores biometric data that enables people's faces to be recognised when they return. It can be used for security, such as to sound an alarm when a known shoplifter enters a shop.

Foodstuffs said: "Like all other retailers, we take theft and the safety of our customers and staff very seriously.

"Theft is a growing problem, as is the increase in aggressive behaviour towards our staff. There is no shortage of incidents resulting in significant harm and sadly, in a recent tragic case, death.

"We use multiple strategies to protect our people, customers and product and we make no apology for this.

"Where CCTV - which may include facial recognition technology - is used in our stores, signage alerts customers to the fact images may be taken, as per privacy requirements.

"Footage can only be used for the purpose it is intended, which is as a deterrent and tool against theft and as a means of keeping customers and staff safe.

"The Auror system, minus facial recognition, is deployed in a number of our South Island stores.

"This system does not include facial recognition but does capture images and licence plate numbers, enabling our loss prevention staff to identify offenders more easily and get on top of theft.

"Some stores in the North Island use a system which includes facial recognition technology.

"The system requires store security to identify the individual as trespassed from the store or as a person known to have shoplifted in our stores, and manually input the information into the system – they will then be picked up by the CCTV on future visits.

"The real benefit here is that the technology greatly assists store security in identifying, monitoring and potentially excluding people with a history of shoplifting. CCTV helps reduce the risk of falsely accusing innocent customers of theft and can assist the Police in their investigations, should it be required. Facial recognition is simply a more accurate version of CCTV."