MPs have called Facebook boss Mark Zuckerberg to attend a parliamentary committee and give evidence about the use of personal data by Cambridge Analytica.
In a letter to Zuckerberg, the committee’s chair, Damian Collins, wrote that social media platform had been repeatedly asked about how other companies used and held data from its site, and whether it had been taken without users’ consent.
The letter which gives a deadline for response of 26 March, states:
"Your officials’ answers have consistently understated this risk, and have been misleading to the committee."
"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 ... Given your commitment at the start of the new year to ‘fixing’ Facebook, I hope that this representative will be you."
On Tuesday, the board of Cambridge Analytica announced it has suspended chief executive Alexander Nix with immediate effect.
Meanwhile, the data watchdog is to apply for a warrant to search computers and servers used by a British firm accused of harvesting personal details from more than 50 million Facebook users.
Prime Minister Theresa May's official spokesman has called on Facebook and Cambridge Analytica to co-operate fully with the investigation by Information Commissioner Elizabeth Denham.
Ms Denham criticised CA for being "unco-operative" with her probe as she confirmed the Information Commissioner's Office (ICO) would apply for a warrant to help her examine the firm's activities.
Facebook has hired a digital forensics firm to investigate allegations.
What is Cambridge Analytica accused of?
Cambridge Analytica was allegedly passed personal data from Facebook apps without the consent of the users.
It is claimed researchers used the data to build personality and psychological profiles on millions of users.
Facebook has ordered digital forensics firm Stroz Friedberg to conduct "a comprehensive audit of Cambridge Analytica" following claims the company carried out a 'data grab' of over 50 million profiles in 2014.
If the data still exists, the company says "it would be a grave violation of Facebook’s policies and an unacceptable violation of trust".
Meanwhile, further details about the firm's activities included claims the company offered to entrap politicians and used ex-spies to dig for dirt on potential targets.
What are the other allegations?
A Channel 4 undercover investigation recorded the non-suspended chief executive suggesting ways he could help a potential client.
Alexander Nix reportedly told an undercover reporter how he could get candidates elected in Sri Lanka.
He is quoted as saying: "Just to go and speak to the incumbents and to offer them a deal that's too good to be true, and make sure that that's video recorded, you know, these sorts of tactics are very effective instantly having video evidence of corruption, putting it on the internet, these sorts of things."
He even suggested CA could "send some girls around to the candidate's house", adding that Ukrainian girls "are very beautiful, I find that works very well", Channel 4 reported.
What has Cambridge Analytica said?
CA told Channel 4: "We entirely refute any allegation that Cambridge Analytica or any of its affiliates use entrapment, bribes or so-called honeytraps for any purpose whatsoever."
The firm added: "Cambridge Analytica does not use untrue material for any purpose."
It later tweeted a defence of its "tactics" and said criticism was born out of envy.
How did the data harvesting allegations first emerge?
The allegations came to light when whistleblower Chris Wylie, a former research director at the UK-based company, told Channel 4 News a so-called data grab had been carried out on more than 50 million profiles in 2014.
Downing Street has said the allegations are "very concerning" and called on the social media giant and CA to co-operate fully with an investigation by Information Commissioner Elizabeth Denham.