POLICE can be sued over their use of live facial recognition technology, a watchdog said ahead of the controversial technology being used to police a protest for the first time tomorrow.

The Biometrics and Surveillance Camera Commissioner Professor William Webster warned the system, set to be used by all police forces in England and Wales, is not “fool proof.”

He said that “misidentified” members of the public could sue the police for breaching their fundamental rights including privacy, freedom of movement and freedom of association.

The Metropolitan Police has said it will use it at the Tommy Robinson-led Unite the Kingdom rally, with cameras set up in a location that is not on the route of the march.

Prof Webster said: “There’s no escaping that the technologies are not fool proof.

“They will make mistakes, and the risk is that every time a mistake is made, a police force will find themselves in a court of law.

“It’s a predictive technology, it’s not meant to be 100 per cent accurate.

“This is why we have to have a legal framework. A legal framework will set out in very clear words what different rights are involved here, where the clash is, and how police forces can mitigate protecting all those rights.”

The legal basis for the technology’s use is currently piecemeal, based on common law, data protection and human rights laws.

The recently set out Police Reform Bill will outline a new legal framework for facial recognition, but concerns remain that legislation is lagging far behind the technology.

Prof Webster warned the technology might have moved beyond simply recognising faces by the time the Bill has made it into law.

Ilyas Nagdee, Racial Justice Lead at Amnesty International UK said: “Facial Recognition Technology is a dangerous and discriminatory tool of surveillance that should be immediately scrapped. The Home Office’s own data shows that it is significantly less accurate in scanning the faces of people of colour. It has led to repeated cases of harassment and false arrest, such as Shaun Thompson. It’s particularly concerning when we consider both the Casey report’s conclusion that the Metropolitan police are guilty of institutional racism, and the lack of Government regulation in this area, leaving police to write their own rules with no accountability or oversight.”