In a sensational development, Facebook reportedly has been accused of spying on Instagram users through their mobile phone cameras.

According to a Bloomberg report, a complaint has been filed in federal court in San Francisco, New Jersey by an Instagram user named Brittany Conditi.

The user, in her complaint, reportedly said that the app's use of the camera phones was intentional and it was done with a view to collect "lucrative and valuable data on its users that it would not otherwise have access to."

The complaint further added, "By obtaining extremely private and intimate personal data on their users, including in the privacy of their own homes, Instagram and Facebook are able to collect valuable insights and market research."

Earlier, Facebook had denied media reports that the photo-sharing app appeared to be accessing iPhone cameras even when they weren't actively being used.