Facebook Inc. (FB.O) uncovered emails that seem to show Chief Executive Officer Mark Zuckerberg was aware of potentially problematic privacy practices at the company, the Wall Street Journal reported, citing people familiar with the matter.

The social media giant discovered the emails in the process of responding to a federal privacy investigation, the Journal reported, raising concerns that it would be harmful to the company if they became public. The potential impact of the internal emails was part of the reason the company sought to reach a quick settlement of the investigation by the Federal Trade Commission, the Journal reported, citing one person familiar with the matter.

The FTC has been looking into whether Facebook violated the terms of its 2012 consent decree with the agency related to privacy issues and the emails sent around that time suggest that Zuckerberg and other senior executives didn’t put compliance with the FTC order at the top of priorities, according to the Journal.

Facebook shares dropped about 2 per cent on the news before recovering slightly.

The company didn’t immediately respond to a request for comment. The Journal said it couldn’t be determined exactly what emails the FTC has requested and how many of them relate to Zuckerberg. It’s also unclear whether any of the emails, described to the Journal, show evidence that the company violated the 2012 agreement.