The Met Police used facial recognition technology to scan 13,000 faces but only one person was arrested.
It has also emerged that the surveillance tactic failed to identify the correct suspect seven out of eight times while it was deployed by the force.
The Met made use of the technology three times last year, scanning faces in East London and Oxford Circus with little result.
Silkie Carlo, director of Big Brother Watch, said: ‘The police’s own data shows facial recognition surveillance is dangerously inaccurate and a waste of public money, let alone a serious assault on our civil liberties.
‘The Government should ban police and retailers alike using this Orwellian tech.’