American billionaire tech entrepreneur, Mark Zuckerberg has admitted that his company has made mistakes, as it emerges more users were hit by a data leak than first feared.
Facebook has said more users may have been affected by the Cambridge Analytica data leak than previously thought, accoridng to Sky News.
Up to 87 million people may have had their personal information taken from Facebook, its chief technology officer Mike Schroepfer wrote in a blog post.
Previous estimates suggested approximately 50 million users were affected by Cambridge Analytica accessing data.
Most of the 87 million people whose data was shared with the political consultancy, which worked on Donald Trump's presidential campaign, were in the US.
A total of 70,632,350 users in the US were affected while 1.079 million users were in the UK.
Mr Schroepfer did not explain how Facebook came to determine that 87 million users were affected.
He said Facebook would tell people if their information may have been improperly shared with Cambridge Analytica.
Facebook is taking steps to restrict the personal data available to third-party app developers, he added.
Facebook chief executive Mark Zuckerberg admitted mistakes were made and said his company has not taken a broad enough view of its responsibility in the world.
He called it a "huge mistake, it's my mistake".
During a conference call to reporters, he said he wishes he could snap his fingers and solve everything in three to six months - but said it would take many years to fix the company's problems.
"These are big issues," he said, adding that the company will have "turned a corner" on a lot of the issues by the end of the year.
From Monday 9 April, Facebook users will be given a link at the top of their news feed so they can see what apps they use and the information they have shared with those apps.
As part of that process people will be told if their information may have been improperly shared with Cambridge Analytica.
The largest social media company in the world - with a billion users - has seen its shares plunge as it faces anger from users, advertisers and politicians after a series of "fake news", election-meddling and privacy scandals.
Mr Zuckerberg will testify over the matter next week before the US House Energy and Commerce Committee, the panel said on Wednesday.
Mr Zuckerberg has so far resisted calls from the British government to face its digital committee over the data leak, which includes allegations about the site being used to influence the Brexit referendum.
Facebook shares were down 1.4% on Wednesday to $153.90 (£108).
They are down more than 16% since the Cambridge Analytics scandal broke on 19 March.