Is Asda Lancaster watching you?

Screens at the self-service checkouts in the Ovangle Road store play back live images of shoppers scanning through purchases, while screens in the foyer area appear to “zoom in” on faces.

Those entering the store now see a bright green square around their heads on TV screens, leading to concern from some shoppers that Asda is storing images.

Asda said that the store did not use facial recognition software, and the technology does not log personal data and is “merely used to enhance image quality and deter thieves”.

One shopper, who did not wish to be named, said: “When I asked about the software in the store I was treated very politely by a security guard, the member of staff on the customer services desk and by the store manager.

“It seemed to me that they had received training about how to deal with customers querying use of this software.

“I was given a website to contact but no other details at all.

“I have e-mailed Asda head office directly with a series of questions but as yet have received no reply.”

The shopper said they were concerned that the supermarket was using the controversial facial recognition software, that they said can be “stored, manipulated, and shared without consent.”

But Asda said that this was not the case.

The BBC reported last year that US retail giant Walmart, which owns Asda, said that it uses image recognition cameras at checkouts in the US to detect theft.

The cameras identify when items are put in a shopping bag without first being scanned by a cashier, or at the self-service checkout.

But a spokesman for Asda said this was not the case in UK Asda stores, and the screens were used purely as a “deterrent”.