You probably don't know it, but you might be leaving something behind when you shop at some of Australia's largest retailers — your face.

Consumer group CHOICE is referring Kmart, Bunnings and The Good Guys to the Office of the Australian Information Commissioner to investigate potential breaches of the Privacy Act over their use of facial recognition technology.

The organisation probed 25 of "Australia's most-trusted retailers", and found Kmart, Bunnings and The Good Guys were "capturing the biometric data of their customers".

CHOICE also surveyed more than 1,000 customers between March and April this year as part of their investigation.

CHOICE consumer data advocate, Kate Bower, said the use of facial recognition by The Good Guys, Kmart and Bunnings was "completely inappropriate and unnecessary".

"To make matters worse, we found 76 per cent of Australians aren't aware that retailers are capturing their unique facial features in this way," she said. 

"Using facial recognition technology in this way is similar to Kmart, Bunnings or The Good Guys collecting your fingerprints or DNA every time you shop. Businesses using invasive technologies to capture their customers' sensitive biometric information is unethical and is a sure way to erode consumer trust."

To create the customer "faceprint", images and video from cameras in a store are analysed.

Ms Bower said Kmart and Bunnings displayed "small signs at the entrance of stores where the technology was in use".

"However, discreet signage and online privacy policies are not nearly enough to adequately inform shoppers that this controversial technology is in use," she said.

"The technology is capturing highly personal data from customers, including infants and children."

The ABC has contacted Bunnings, The Good Guys and Kmart for comment.

Bunnings' chief operating officer Simon McDowell told CHOICE the technology was used to "identify persons of interest who have previously been involved in incidents of concern in our stores".

"This technology is an important measure that helps us to maintain a safe and secure environment for our team and customers," he said.

"We let customers know about our use of CCTV and facial recognition technology through signage at our store entrances and also in our privacy policy, which is available on our website."

Respondents to CHOICE's survey described the tech as "creepy and invasive" while others considered it "unnecessary and dangerous".

Of the more than 1,000 respondents, 65 per cent said they were concerned about stores using the technology to create profiles of customers that could cause them harm.

"I think that's where people start to become concerned, that this could be used in ways that could really hard for an average consumer to understand," CHOICE chief executive officer Alan Kirkland said.

Monash University media professor, Mark Andrejevic, said the technology was likely to become more widespread as it became more affordable and effective.

"The first concern is notice and consent, it's not in highly visible forms of public notification that would invite people to understand what's taking place," he said. 

"I think the other set of concerns is we don't have a clear set of regulations or guidelines on the appropriate use of the technology."

Former Human Rights Commissioner, Edward Santow, flagged concerns around surveillance.

"Even if that technology was perfectly accurate, and it's not, but even if it were, it also takes us into the realm of mass surveillance," he said. 

"And I think there will be great concern in the Australian community about walking down that path."

CHOICE is also calling on the federal government to create a guide to protect consumers who don't want their "faceprint" on file.