Hong Kong law enforcement authorities have access to artificial intelligence software that can match faces from video footage to police databases, but people familiar with the matter say it is unclear if the technology is being used to quell the pro-democracy protests.

Police have been able to use the technology from the Sydney-based iOmniscient for at least three years, and engineers from the company have trained dozens of officers on how to use it, said the people, who asked not to be identified because the information isn't public. The software can scan footage, including from closed-circuit television, to match faces and license plates to a police database and pick out suspects in a crowd.

In addition to tracking criminals, iOminiscient's artificial intelligence can be used for everything from finding lost children to managing traffic.