The technology has the potential to alter privacy as we know it, according to Andrew Ferguson, a law professor at American University.

Facial recognition is "going to change the relationship between the people who surveil and the people who are being surveilled," he said.

Founded by Hoan Ton-That, Clearview AI uses a database of 3 billion images, which allows police to use a photo of a suspect to find other images and information about that person from across the internet.

"We have millions and millions of different websites all around the web that we crawl and add to our database," he told the ABC's The World Today program

his statement has drawn the interest of Australian privacy commissioner Angelene Falk, who said she wanted to know whether the data of Australians had been collected.

"It has caught my regulatory attention and I am making inquiries of Clearview AI to ascertain whether or not Australians' data is implicated," she told RN Breakfast.

Mr Ton-That, 31, grew up in Australia and moved to the US at 19 years old. He worked in app development and as a part-time model before founding Clearview AI four years ago.

Is Clearview AI being used by police in Australia?

A report in The New York Times earlier this week uncovered the use of Clearview AI by more than 600 police departments.

"There's a lot of crimes and cases that are being solved," Mr Ton-That said.

"We really believe that this technology can make the world a lot safer."

Mr Ton-That claims police in Australia are using his technology.

"We have a few customers in Australia who are piloting the tool, especially around child exploitation cases."

Mr Ton-That would not specify which police departments used Clearview AI.

The ABC contacted police in all states and territories, as well as the AFP and Home Affairs.

Of those which responded, all said they use facial recognition in some capacity except NSW Police, which denied reports it was using facial recognition.

All said they did not use Clearview AI, except for Victoria Police, which said, "for security reasons, Victoria Police does not comment on the specifics of the technology."

Queensland and Western Australia did not respond in time for publication.

Ms Falk told RN Breakfast any police department would need to have completed a privacy impact assessment if it intended to use Clearview AI's technology.

"The Australian privacy principles would require them to conduct a privacy impact assessment, that means looking at what are the privacy risks, how would the information be handled and how those risks would be mitigated," she said.

She added that she would have oversight of the use of such technology, as she has with uses of facial recognition that have already been approved, such as at airports for fast-tracked immigration screening.

Could your Facebook photos be used by Clearview?

Clearview AI has also been criticised by privacy advocates for its practice of scraping facial images from social media, including Facebook and YouTube.

A spokesperson from Facebook told the ABC the tech giant could take action against Clearview AI over the practice.

"Scraping Facebook information or adding it to a directory are prohibited by our policies," they said.

"We are reviewing the claims about this company and will take appropriate action if we find they are violating our rules."

In response to questions about scraping images from social media, Mr Ton-That said: "There's many things we want to talk about, and, you know, one thing's not Facebook."

"The general public does understand that things that are public do get into search engines and other places."

But Monique Mann, from the Australian Privacy Foundation, said people had a right to be concerned if their biometrics were harvested from social media channels.

"Their sensitive personal information — biometric information is sensitive information — has been taken without their knowledge or their consent, and it's been put to use for applications that they were not aware of and they certainly haven't agreed to," Dr Mann said.

Ms Falk said if sensitive biometric data of Australians had been collected, Clearview AI would have to abide by Australia's privacy act, which would require informed consent.

Experts call for regulation

Australia lacks regulations to handle the advent of facial recognition technology, according to Dr Mann.

"If they [police] were to use it, it needs to operate within a robust human rights-based regulatory framework, which in the current Australian context is notably absent," she said.

Professor Ferguson said any police use of face identification should be strictly limited.

"I certainly don't think police should use it without rules, without regulations, without limits, and without controls and audits and transparency."

Professor Ferguson added that real-time facial recognition, which is already being used in China, should be banned outright.

The New York Times investigation found Clearview AI had prototyped the ability to use real-time facial recognition built into augmented reality glasses, but Mr Ton-That said the company was not pursuing real-time surveillance.

"It's not on our roadmap," he said, explaining their tools were "search, not surveillance, so it's an after-the-fact research tool."

But he agreed, regulation of facial recognition should be looked at.

"Oversight would be a great thing," he said.

"I think it would help to put the general public at ease."

Mr Ton-That said he was confident the technology was not being misused.

"We have a strong belief that law enforcement do the right thing with the tool and we have seen zero abuse so far," he said.