San Francisco: Facebook CEO Mark Zuckerberg did not knowingly violate an agreement with the regulator supervising the company's management of users' personal data, the social media giant said Wednesday as it addressed an issue that has been under federal investigation for the past year.

Facebook was required to provide the Federal Trade Commission (FTC) with emails, some from 2012, suggesting that Zuckerberg was personally aware of but neglected to address the fact that external applications had access to massive amounts of personal data without Facebook users' knowledge, the Wall Street Journal reported. The newspaper added that it did not have access to the documents but that anonymous sources had described their contents.