Consumer privacy advocates have responded with alarm after Coles and Woolworths confirmed they were testing facial recognition technology that they could use in their Australian supermarkets to record shoppers’ personal biometric data.

The supermarket giants on Monday confirmed they had tested the technology and said they were considering installing it in their Australian stores to crack down on retail crime including aggression towards staff.

Woolworths and Coles said they had not made a final decision on whether to proceed with the rollout, and neither supermarket chain would disclose which company had provided them with the software they had tested.

Dr Jason Pallant, a marketing expert at RMIT University, said the trials posed a “security versus privacy dilemma”.

“We all agree that security and safety for retail staff is important, but … that means every person who enters a supermarket is accepting their face being scanned,” he said.

“The solution is actually really being transparent and educating consumers about how it works.”

The supermarkets’ exploration of facial recognition software follows a decision by the administrative review tribunal in February to greenlight Bunnings’ use of the technology on its customers.

After an appeal by Bunnings, the tribunal reversed a 2024 ruling by the privacy commissioner that had found the hardware giant breached the privacy of store visitors by scanning and checking their faces.

The tribunal agreed, however, that Bunnings had not properly notified customers that their faces were being scanned.

Facial recognition technology captures images of people’s faces from video cameras – such as CCTV footage – as a unique faceprint that is then stored and can be compared with other faceprints.

Retailers may compare the faceprints against a watch list of known aggressive or banned people in an attempt to reduce violence in their stores.

In addition to concerns about surveillance and the storage of personal information, facial recognition is controversial because there has been evidence of misuse and that people of colour are more likely to be incorrectly identified than white people.

Tom Sulston, the head of policy at Digital Rights Watch, said facial recognition was “wildly inaccurate”.

Sulston said he was also concerned shoppers at Woolworths and Coles would not be able to control the way their biometric data was used.

“It grossly disproportionate for retailers, especially food retailers, to be using that technology,” he said.

“Supermarkets are pretty safe places where ordinary people need to go in order to feed themselves and we shouldn’t have to pay with our privacy to do that.”

A spokesperson for Coles said it had “not done a trial using this technology” and instead had undertaken a “small, one-off, controlled proof-of-concept test”, which did not use customer or team member information or data.

“We will always explore technology that will help us keep our team and customers safe.”

A spokesperson for Woolworths, which tested the technology at its offices in New Zealand, said it would “continue to trial a range of initiatives to ensure the safety of our team and customers”.

“While our current safety initiatives are making a difference, we are still seeing a concerning number of incidents of aggression and conflict in our stores on a daily basis, including weapons being presented,” Woolworths said.

Dr Luke Munn, a research fellow at the University of Queensland’s Centre for Digital Cultures and Societies, said he was concerned the technology could be used beyond its initial stated purpose.

“Aggression towards staff is not OK, but I also see that as a way to shoehorn this technology into a lot of [retail] infrastructure at the core of everyday life for Australians, which is normalising surveillance,” he said.

If Woolworths and Coles use facial recognition technology in their stores, this would follow the recent installation of anti-theft gates and self-service checkouts, which were a technological replacement for human staff.

Munn said the major supermarkets had a history of “using technology to fix problems which creates more problems”.

“Theft would be mitigated if you were actually paying a worker for your groceries.”