The company is banned from selling its services to most US companies, after the American Civil Liberties Union (ACLU) took Clearview AI to court in Illinois for breaking privacy law.
But there is an exemption for police, and Mr Ton-That says his software is used by hundreds of police forces across the US.
Police in the US do not routinely reveal whether they use the software, and it is banned in several US cities including Portland, San Francisco and Seattle.
The use of facial recognition by the police is often sold to the public as only being used for serious or violent crimes.
Clayton, J., & Derico, B. (2023, March 27). Clearview AI used nearly 1m times by US police, it tells the BBC. BBC News. https://www.bbc.com/news/technology-65057011