Clearview AI offers its clients a system that works like a search engine for faces - users upload a photo and it finds matches in a database of billions of images it has collected.It then provides links to where matching images appear online.

In March, Clearview's founder Hoan Ton-That said it had run nearly a million searches for US police, helping them to solve a range of crimes, including murders.

He also revealed its database contained 30 billion images scraped from the internet.

Critics argue that law enforcement's use of Clearview's technology puts everyone into a "perpetual police line-up".

France, Italy and Australia had also taken action against the firm.