London (AFP) - The university academic, the chief executive who boasted about dirty tricks and US political strategist Steve Bannon -- here are the key figures involved in Cambridge Analytica, the British firm at the heart of a Facebook data scandal:
- The academic -
Aleksandr Kogan was the University of Cambridge researcher who developed the app This Is Your Digital Life, which was used to take the data from Facebook.
Developed through his commercial company Global Science Research, it offered a small financial payment in return for users filling out a personality test.
Facebook says it was downloaded by 270,000 people, but it also gave Kogan access to their friends, giving him a wealth of information which a whistleblower said extended to up to 50 million users.
The data was passed to Cambridge Analytica, but the company has blamed him for misusing it -- while he claims they and Facebook have used him as a scapegoat.
Born in Moldova and raised in Russia, before emigrating to the United States at the age of seven, Kogan studied at the University of California, Berkeley, and obtained his doctorate at the University of Hong Kong.
He is a lecturer at Cambridge's Department of Psychology, and has worked with St Petersburg University, as well as reportedly receiving Russian government research grants.
- The CEO -
Alexander Nix, the 42-year-old chief executive of Cambridge Analytica (CA), was suspended after he was filmed by undercover reporters bragging about ways to win political campaigns, including through blackmail and honey traps.
He was filmed by Channel 4 television claiming to have done all the analytics and run all the digital campaigns for Donald Trump's 2016 presidential election campaign.
In suspending him, CA said his comments "do not represent the values or operations of the firm".
Educated at the elite British boarding school Eton College and the University of Manchester, Nix worked in corporate finance before joining the SCL group, which owns CA.
According to The Guardian/Observer newspapers, he developed the political arm of the data analysis company, which has seen its involvement in numerous election campaigns around the world.
- The whistleblower -
Christopher Wylie, a 28-year-old Canadian data analytics expert who worked with Cambridge Analytica and Kogan, blew the whistle on the scandal by revealing that more than 50 million Facebook profiles had been accessed without approval.
A graduate of the London School of Economics university who initially worked with Britain's small Liberal Democrats party, he claims he helped set up the CA project, as well as helping forge its contacts with US strategist Bannon and wealthy Republican donor Robert Mercer.
Facebook suspended his account when the story broke, while CA says he is a former contractor who left in 2014 and has been "misrepresenting himself and the company" in his comments to the media.
- The investor -
Robert Mercer and his family are long-time backers of conservative causes in the United States, and reportedly invested $15 million (12.2 million euro) in Cambridge Analytica.
A former IBM computer scientist, Mercer became a dollar billionaire through his work with Long Island-based Renaissance Technologies, a computer-driven hedge fund.
He quit in November due to the media scrutiny of his role backing Trump and his former strategist Bannon, which included investing heavily in Bannon's Breitbart News.
- The strategist -
Steve Bannon is a former board member of Cambridge Analytica and brought in Mercer as a financial backer, according to The Guardian/Observer newspapers.
He helped push a populist, anti-Washington message from the helm of provocative rightwing website Breitbart News and was a key figure in Trump's election.
He left the White House in August last year and Trump has since cut him off, while Bannon has also stepped down from Breitbart News.