Ex-Cambridge Analytica employee believes over 87 million Facebook users had data compromised

A former director with Cambridge Analytica, which is at the centre of a scandal over the use of Facebook data, testified Tuesday before a British House of Commons committee that she believed the number of Facebook users compromised in similar ways was "much greater" than the current estimate of 87 million.

Brittany Kaiser admitted she was not a data expert, but was making her supposition based on the knowledge of at least two quizzes Facebook users took that were different than the one Cambridge is said to have been employed in developing U.S. voter profiles.

"Therefore it can be inferred or implied that there were many additional individuals … whose data may have been compromised," Kaiser, who was director of business development with the political consultancy, said in London.

It was not clear, however, for what purposes, if any, the other quizzes were used.

Kaiser appeared before the committee a day before the highly anticipated turn of Alexander Nix, but it was learned that the suspended Cambridge CEO wouldn't be testifying Wednesday.

Damian Collins, chairman of a parliamentary committee, made the announcement.

"His legal representation has said that he's now not able to give evidence to the committee tomorrow [Wednesday], as a consequence of him having been served an information notice, and being subject to a criminal investigation by the Information Commissioner's Office," Damian Collins, chair of the digital, culture, media and sport committee, said at the public session.

Collins said he was considering a formal summons for Nix, and hoped to provide an update on a date for a new hearing early next week.

"We do not accept Mr Nix's reason for not appearing in a public session before the committee," Collins said in an emailed statement. "There is therefore no legal reason why Mr. Nix cannot appear."

Cambridge was hired by Donald Trump's campaign for his 2016 U.S. presidential election campaign.

Brexit group claims angrily denied

The analytics firm is also under scrutiny over alleged campaigning for the 2016 referendum when Britons voted to leave the European Union.

On Tuesday, a prominent campaigner to leave the EU, Arron Banks, denied allegations he had misused personal data for political purposes.

Kaiser testified to the committee that Leave.EU founder Banks might have broken data protection law by mixing customer data from his insurance firms with voter contact lists.

Kaiser said that on a visit to Banks's headquarters in Bristol, she had seen a call centre where data for Eldon and GoSkippy, Banks's insurance firms, was being used by Leave.EU.

"In hindsight, I now think that there is reason to believe that misuse of data was rife amongst the businesses and campaigns of Arron Banks," she said in written testimony to the committee.

Banks told Reuters the testimony was "sheer whoppers."

He said it was well known that Leave.EU had set up a call centre in his offices, but there was a separate dataset for politics, and there was "no overlap at all."

"We absolutely refute that any insurance data was used in it," he added.

Cambridge Analytica said it had "never received data from any Arron Banks company," in a tweet, as Kaiser gave her testimony.

Cambridge Analytica and Banks, who was a major donor to euroskeptic party UKIP, have said that while the consultancy pitched for work with Leave.EU, it did not have any contracts and no money changed hands.

Banks reiterated that Leave.EU decided not to use Cambridge Analytica after his campaign was not designated as the official campaign to leave the European Union.

Collins has said Leave.EU still benefited from work done before that decision was made.