The privacy regulator said it was “deeply concerned” about the increasing use of facial recognition technology in public spaces.

Under the General Data Protection Regulation (GDPR), facial images are categorised as ‘sensitive personal data’, which organisations require explicit consent to collect.

The use of facial recognition technology in the area around King’s Cross station was first reported by the Financial Times on Monday ( 12th August).

Camden Council told the BBC it was unaware the technology was being used. Argent, the developer behind the site, has said in a statement it used the tool to “ensure public safety”.

Information commissioner Elizabeth Denham said: “Facial recognition technology is a priority area for the ICO and when necessary, we will not hesitate use our investigative and enforcement powers to protect people’s legal rights.

“We have launched an investigation following concerns reported in the media regarding the use of live facial recognition in the King’s Cross area of central London, which thousands of people pass through every day.”

The ICO said it would inspect the technology and its operation to see how it is used and whether it complies with data protection law.

Denham added: “Any organisations wanting to use facial recognition technology must comply with the law – and they must do so in a fair, transparent and accountable way. They must have documented how and why they believe their use of the technology is legal, proportionate and justified.”