Doubts have been raised over the sincerity of scandal-hit political analysis firm Cambridge Analytica’s announcement it is ending operations.

Cambridge Analytica, which worked on the Brexit and Donald Trump campaigns, announced on Thursday it was declaring bankruptcy and shutting down.

The company sustained severe criticism after harvesting the data from millions of Facebook profiles.

The move followed rising legal costs in the Facebook investigation and the loss of clients following revelations about the firm in March.

But the announcement has been met with skepticism after reports several key personnel at Cambridge Analytica were recently involved in setting up a new data company called Emerdata.

Cambridge Analytica said in a statement it had been “vilified” for legal activities that are a “standard component” of advertising in the political world, and blamed the “siege of media coverage” for driving away “virtually all of the company’s customers and suppliers”.

The Cambridge Analytica statement made no reference to Emerdata, which is located at the same London building.

Business Insider reported two daughters of Cambridge Analytica founder Robert Mercer – Rebekah and Jennifer Mercer – joined the Emerdata board in March, while Cambridge Analytica’s suspended CEO Alexander Nix was named as a director in January but was removed on March 28.

UK and US media reported that filings at Britain’s Companies House on Emerdata said Cambridge Analytica’s chief data officer, Alexander Tayler, set up the company alongside Julian Whatland, the chairman of the disgraced data firm’s parent company SCL Group.

SCL Group will also shut down alongside Cambridge Analytica, the Wall Street Journal reported.

Up to 87 million people had data harvested by an app which was then acquired by Cambridge Analytica, according to Facebook.

The app, a personality survey called This Is Your Digital Life, collected personal data from users and their Facebook friends, in line with the behaviour of many similar apps at the time.

It allowed Cambridge Analytica to tailor specific political adverts to small groups of people, already knowing what their likes and interests were, it is alleged.

Cambridge Analytica played a key role in mapping out the behaviour of voters in the run-up to the 2016 US election and was also used during the EU referendum campaign earlier that year.

Cambridge Analytica was created in 2013, initially with a focus on US elections, with $US15 million ($20 million) in backing from billionaire Republican donor Robert Mercer, The New York Times reported.

-with agencies