Facebook has been plunged into crisis over the allegations that Cambridge Analytica misused data from more than 50 million people to help elect Donald Trump. Nearly $40 billion was wiped off Facebook’s market value Monday, an emergency meeting is due to be held Tuesday morning, and CEO Mark Zuckerberg has been criticized for remaining silent during what some analysts are describing as a threat to the company’s existence.

Zuckerberg has been summoned to the British parliament to give evidence about the how it handles people's personal data. The head of a British inquiry into 'fake news,' Damian Collins, has accused Facebook of previously 'misleading' a parliament committee, adding: "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."

As anger grew toward Cambridge Analytica on Monday after Britain’s Channel 4 broadcast a report showing company executives boasting about their extreme propaganda strategies, including filming opponents in compromising situations with Ukrainian sex workers, authorities in the U.K. and the U.S. also questioned whether Facebook mishandled the alleged breach and it’s now facing damaging investigations that will further tarnish its brand.

Britain’s information commissioner, Elizabeth Denham, confirmed she was applying to the courts for a warrant to search Cambridge Analytica’s London offices and said Tuesday morning that she has been left frustrated by the company’s reluctance to cooperate with her investigation.

Fears have also been raised that the investigation may have been compromised by the presence of cybersecurity consultants from Stroz Friedberg—the company hired by Facebook to audit Cambridge Analytica on its behalf—who were in the London offices on Monday evening, until they were asked to leave by the information commissioner.

Asked if there was a risk of Cambridge Analytica or Facebook destroying evidence, Denham said on Sky News: “As this point we’re not satisfied with the cooperation we’re getting from Cambridge Analytica, so the next step is for us to apply to the court and to do an audit to get some answers as to whether data was misused and shared inappropriately.”

British Parliament Culture Committee Chairman Damian Collins said: “This is a matter for the authorities. Facebook sent in data analysts and lawyers who they appointed. What they intended to do there, who knows? The concern would have been, were they removing information or evidence which could have been vital to the investigation? It’s right they stood down but it’s astonishing they were there in the first place.”

Denham said Facebook itself will be subject to an investigation over its actions, saying: “We are looking at whether or not Facebook secured and safeguarded personal information on the platform and whether when they found out about the loss of the data they acted robustly and whether or not people were informed.”

In the U.S., Sen. John Kennedy (R-LA) has called on Zuckerberg to testify before Congress, and Sen. Ron Wyden (D-OR) sent a letter to the Facebook CEO to inquire about the company’s policies for sharing user data with third parties. It’s unlikely Zuckerberg will appear before Congress, as the company usually sends lawyers in place of company figures.

Congress has also called on Cambridge Analytica Chief Executive Alexander Nix to be hauled in for questioning. Adam Schiff, the top Democrat on the House intelligence committee, said it was particularly pressing for Nix to be interviewed after reports that the academic who worked on the data-harvesting tool, Aleksandr Kogan, also received grants from the Russian government to research Facebook users’ emotional states.

Schiff said: “Reports that an American professor with links to Russia was at the center of this illicit transfer of information raises further questions, which the committee must investigate. Despite our request, and as set out in our status report, the committee has not had the opportunity to talk with numerous Cambridge Analytica personnel who may have knowledge of this and other issues—they must now be brought in for interviews.”

Nix is accused of lying to the British parliament, where he claimed his company hadn’t collected any personal data without people’s consent via Facebook, but it’s not clear what punishment that would incur. If brought before Congress, he would be under oath and obliged to tell the truth.

The whistleblower who raised the misuse of data, Christopher Wylie, also raised the links between Cambridge Analytica and Russia on Tuesday, saying on NBC News: “This company misappropriated data of upwards of 50 million people from Facebook. They misused that data. That data was processed by psychologists who were going back and forth between London and Russia, who are also working on projects in Russia for Russians.

“This company was using this data meanwhile as it was talking to the second largest oil company of Russia [and] sending work that I was doing to the CEO of Lukoil, which has known links with the Russian FSB ,which is their state security services. I think we need to step back for a second and depoliticize this because this is about the safety of Americans and the integrity of the American democratic process.”

Wylie also told CNN that Cambridge Analytica tested possible Trump slogans, such as “drain the swamp” and “build that wall,” as early as 2014—before his presidential run was announced.

Wylie said: “A lot of these narratives which at the time would have seemed crazy for a mainstream candidate to run on, those were the things we were finding there were pockets of Americans who this really appealed to. Steve Bannon knew that, because we were doing the research on it.”

“We were testing these narratives well before Trump even announced.”

Meanwhile, a new whistleblower and former Facebook insider told The Guardian that hundreds of millions of people are likely to have had their data harvested by companies using similar methods as Cambridge Analytica. He said he warned warned senior executives at the company that its poor data protection risked a major breach.

“My concerns were that all of the data that left Facebook servers to developers could not be monitored by Facebook, so we had no idea what developers were doing with the data,” said Sandy Parakilas.