Eight trials carried in London between 2016 and 2018 resulted in a 96 per cent rate of “false positives” – where software wrongly alerts police that a person passing through the scanning area matches a photo on the database.
Two deployments outside the Westfield in shopping centre in Stratford last year saw a 100 per cent failure rate and monitors said a 14-year-old black schoolboy was fingerprinted after being misidentified.
Police allegedly stopped people for covering their faces or wearing hoods, and one man was fined for a public order offence after refusing to be scanned in Romford.
Scotland Yard called the trials “overt” but The Independent found shoppers unaware facial recognition was being used, and campaigners accused police of rolling out the technology “by stealth”.