The Federal Trade Commission has opened an investigation into whether Facebook violated an agreement with the agency on data privacy, after reports that information on 50 million users was improperly obtained by the political consulting firm Cambridge Analytica, according to a person with knowledge of the inquiry.

The investigation, started in recent days, adds to the mounting pressure against Facebook in the United States and in the United Kingdom about its handling of the data. Cambridge Analytica used the information to help President Donald Trump’s presidential campaign profile voters during the 2016 election.

Meanwhile, politicians in the US and the UK want to hear from Facebook Mark Zuckerberg about data privacy. And the head of Cambridge Analytica has been suspended, while government authorities are bearing down on both the firm and Facebook.

Cambridge’s board of directors suspended CEO Alexander Nix pending an investigation after Nix boasted of various unsavory services to an undercover reporter for Britain’s Channel 4 News.

Channel 4 News broadcast clips Tuesday that also show Nix saying his data-mining firm played a major role in securing Donald Trump’s victory in the 2016 presidential elections.

Nix said the firm handled “all the data, all the analytics, all the targeting” and said Cambridge used emails with a “self-destruct timer” to make its role more difficult to trace.

“There’s no evidence, there’s no paper trail, there’s nothing,” he said.

In a statement, Cambridge’s board said Nix’s comments “do not represent the values or operations of the firm and his suspension reflects the seriousness with which we view this violation.”

Cambridge has denied wrongdoing, and Trump’s campaign has said it didn’t use Cambridge’s data.

Zuckerberg summond

Facebook also drew continued criticism for its alleged inaction to protect users’ privacy. Earlier Tuesday, the chairman of the U.K. parliamentary media committee, Damian Collins, said his group has repeatedly asked Facebook how it uses data. He said Facebook officials “have been misleading to the committee.”

The committee summoned Zuckerberg to testify.

“It is now time to hear from a senior Facebook executive with the sufficient authority to give an accurate account of this catastrophic failure of process,” Collins wrote Zuckerberg. “Given your commitment at the start of the New Year to ‘fixing’ Facebook, I hope that this representative will be you.”

Leading Democrats in the U.S. Senate also called on Zuckerberg to testify. Sen. Dianne Feinstein of California, the top Democrat on the Senate Judiciary Committee, called Facebook’s latest privacy scandal a “danger signal.” She wants Zuckerberg’s assurances that Facebook is prepared to take the lead on security measures that protect people’s privacy — or Congress may step in.

Facebook sidestepped questions on whether Zuckerberg would appear, saying instead that it’s currently focused on conducting its own reviews.

The FTC and Facebook reached a settlement in 2011 after the agency accused the company of deceiving customers “by telling them they could keep their information on Facebook private, and then repeatedly allowing it to be shared and made public,” according to a statement at the time.

FTC ‘aware’

Among several violations, the FTC found that Facebook told users that third-party apps on the social media site, like games, would not be allowed to access data. But the apps, the agency found, were able to obtain almost all personal information about a user.

“We are aware of the issues that have been raised but cannot comment on whether we are investigating,” an FTC spokeswoman said in a statement Tuesday. “We take any allegations of violations of our consent decrees very seriously.”

Sens. Amy Klobuchar, D-Minn., and John Kennedy, R-La., have asked to hold a hearing on Facebook’s links to Cambridge Analytica. Republican leaders of the Senate Commerce Committee, led by John Thune of South Dakota, wrote a letter Monday to Mark Zuckerberg, Facebook’s chief executive, demanding answers to questions about how the data was collected and if users were able to control the misuse of data by third parties.

“The possibility that Facebook has either not been transparent with consumers or has not been able to verify that third party app developers are transparent with consumers is troubling,” Thune said in the letter.

On Tuesday morning, a committee within the British Parliament sent a letter to Zuckerberg asking him to appear before the panel to answer questions on the company’s connection to Cambridge Analytica.

“The committee has repeatedly asked Facebook about how companies acquire and hold on to user data from their site, and in particular about whether data had been taken without their consent,” wrote Damian Collins, chairman of the British committee. “Your officials’ answers have consistently understated this risk, and have been misleading to the committee.”