Facial-recognition: How Sports Direct and Spar are using Chinese-made cameras to spot shoplifters

Sports Direct, Spar, Budgens, Costcutter and Southern Co-op are now among the growing number of British retailers using a controversial Chinese state-owned facial-recognition system. The biometric cameras work by scanning the faces of shoppers so they can be checked against a database of suspected criminals. But they have been branded'Orwellian' and'unlawful' by critics, who claim that staff could add people to a secret'blacklist' without them knowing. So how does the facial-recognition system work, and which shops are already using it? Here, MailOnline breaks down everything you need to know about the controversial technology.