US tech giant Microsoft Corp. has secretly deleted an online database that contained more than 10 million images of about 100,000 people, US media reported on Thursday.

The database, also known as MS Celeb, stored images scraped via internet search engines and videos under the Creative Commons license that allows the re-use of the photos for academic research, the CNET media reported.

MS Celeb, which was originally published in 2016, was reportedly the largest public facial recognition dataset in the world before it was taken down, and the images were gathered and used without the consent of the picture owners.

The report said the database was used to train facial recognition systems around the world and could be accessed by military researchers.

The database was first reported by the London-based Financial Times, which contained images of what the daily called "arguably private individuals."

Microsoft told the newspaper that the "site was intended for academic purposes."

"It was run by an employee that is no longer with Microsoft," explained the US software giant.

Microsoft has called for enhanced regulation of artificial intelligence technology to prevent the potential for abuse.

Microsoft President Brad Smith disclosed in April that the company had declined a request from California law enforcement department to sell equipment powered by face recognition technology to arm its police force.