A row has erupted over 's trial of facial recognition technology at five of its Greater Manchester stores.

Asda announced it would be using the , supplied by FaiceTech, at its Ashton, Chadderton, Eastlands, Harpurhey and Trafford Park outlets to combat a surge in shoplfiting.

Privacy campain group Watch claimed Asda had been sent around 5,425 emails complaining about the use of the technology.

Asda denied the reports and said it had only received 89, the Retail Gazette reported.

Asda's trial of the technology involves using its CCTV network. Shoppers in the stores in the trial have their faces scanned which are then compared to images of people have previously committed offences at an Asda site.

The Grocer explained that if the automated system detects a match, a member of the retailer's head office security team will conduct a check and feedback to the store in real time.

But Madeleine Stone, senior advocacy officer at Brother Watch's said the trail was "turns shoppers into suspects, by subjecting customers browsing the supermarket aisles to a series of biometric identity checks".

She claimed facial recognition had well-documented issues with accuracy and bias, and had already led to distressing and embarrassing cases of innocent shoppers being publicly branded as shoplifters.

Asda does not receive photos from the police but instead collects still images from in-store CCTV of individuals staff suspect may be involved in "theft, violence and/or fraud in Asda stores", though they may not be convicted of any crime.

Stone said: "Asda's decision to deploy Orwellian facial recognition technology in its shops is deeply disproportionate and chilling. Facial recognition surveillance turns shoppers into suspects, by subjecting customers browsing the supermarket aisles to a series of biometric identity checks.

"Asda is adding customers to secret watchlists with no due process, meaning people could be blacklisted despite being innocent. Facial recognition has well-documented issues with accuracy and bias, and has already led to distressing and embarrassing cases of innocent shoppers being publicly branded as shoplifters.

She urged Asda to abandon this trial and the government step in to prevent the unchecked spread of what Stone said was "invasive technology".

Big Brother Watch has urged the supermarket to immediately abandon its trial of the technology.

The Daily Express has contacted ASDA for comment.