The Federal Trade Commission said it is opening an investigation into Facebook after news reports raised "substantial concerns about the privacy practices of Facebook."
A statement from Tom Pahl, acting director of the Federal Trade Commission’s Bureau of Consumer Protection, said: "the FTC takes very seriously recent press reports raising substantial concerns about the privacy practices of Facebook."
The FTC probe comes amid reports that data analytics firm, Cambridge Analytica, allegedly misused Facebook data from up to 50 million user profiles. Some members of Congress and privacy advocates have pushed for the FTC to look into whether the matter violates a 2011 consent decree in which Facebook said it would uphold a number of privacy protections.
Facebook's CEO Mark Zuckerberg signed his name in ads taken out in newspapers in the U.S. and the United Kingdom on Sunday apologizing for its failure to protect user information. "This was a breach of trust, and I'm sorry we didn't do more at the time. We're now taking steps to make sure this doesn't happen again," the ads said.
The Senate Judiciary invited Zuckerberg to testify at an April 10 hearing on data privacy. ABC News has reached out to Facebook for a response.
In a statement, Cambridge Analytica said, that in cooperation with the social media company, it had deleted all the Facebook data and related information in 2015. The data firm said that such information was not used as part of its work with the 2016 Trump presidential campaign.
"This Facebook data was not used by Cambridge Analytica as part of the services it provided to the Donald Trump presidential campaign; personality targeted advertising was not carried out for this client either," Cambridge Analytica said in a statement. "The company has made this clear since 2016.”
Cambridge Analytica has also previously said it was unaware the data was improperly obtained by a third party and that it was destroyed as soon as they were made aware.
That third party, Aleksandr Kogan, the Cambridge University researcher who collected information on millions of Americans through Facebook for Cambridge Analytica, told ABC News that both the social media giant and the data firm are making him a “scapegoat.”
The Trump campaign has said it never used data from Cambridge Analytica.
Cook County in Illinois is suing Facebook and Cambridge Analytica for "harvesting of Facebook user data" and Facebook for not protecting the data.
Additionally, 37 state attorneys general sent a letter to Facebook Monday demanding to learn more about the social network's practices, privacy protections and the scope of the data breach.
ABC News’ Lucien Bruggeman contributed to this report.