US regulators have met to discuss imposing a fine against Facebook Inc for violating a legally binding agreement with the government to protect the privacy of personal data, the Washington Post reported on Friday, citing three people familiar with the discussions.

The Federal Trade Commission has been investigating Facebook since last year. It has not finalized its findings in the probe or the total amount of the penalty, according to the newspaper.

Facebook has talked with FTC staff about the investigation, one of the people familiar with the matter told the Post. However, it is unclear if the company would settle with the FTC by accepting a significant financial penalty, which is expected to be much larger than the $22.5 million fine the agency imposed on Alphabet Inc's Google in 2012, the report said. Facebook declined to comment.

The FTC, which is affected by the US government shutdown, did not immediately respond to a request to comment. Generally secretive, it took the unusual step last March of announcing the opening of an investigation into Facebook's privacy practices.

The announcement followed news reports that revealed lax oversight by the social media company had enabled a quiz app on Facebook to gather details on 87 million users and share it with now-defunct British political consulting firm Cambridge Analytica.

Facebook has since acknowledged several other lapses in protecting user data, drawing additional scrutiny from regulators around the world.