Eighteen UK enforcement officers have spent the night searching Cambridge Analytica's London office after the High Court granted a warrant.

The Information Commissioner's Office applied for the legal order to access the company's records and data amid allegations it illegally harvested information from 50 million Facebook users.

The ICO said it was "pleased with the decision of the judge."

"This is just one part of a larger investigation into the use of personal data for political purposes and we will now need time to collect and consider the evidence," it said.

Enforcement officers from the UK Information Commissioner's Office search the premises of Cambridge Analytica in central London, 23-03-2018. Image: Yui Mok/PA Wire/PA Images

Their search began at 8pm on Friday, with officials seen taking photos of a whiteboard and computers and taking notes on a clipboard. Some of the team emerged from the building on foot at around 2.50am on Saturday.

Meanwhile it has emerged that Cambridge Analytica pitched to work for Leave.EU ahead of the European Union referendum but was never hired.

The London-based, which uses data to change the behaviour of internet users, was hired by Donald Trump's campaign team during the 2016 presidential race.

There are claims the information it unlawfully obtained was given to Mr Trump's campaign strategists to provide an insight into the thoughts of American voters, ultimately influencing the election.

Enforcement officers from the UK Information Commissioner's Office search the premises of Cambridge Analytica in central London, 23-03-2018. Image: Yui Mok/PA Wire/PA Images

The data watchdog's investigation includes the acquisition and use of the data by Cambridge Analytica, its parent company SCL and academic Dr Aleksandr Kogan.

Dr Kogan is the University of Cambridge professor who developed the app 'This Is Your Digital Life' through his company Global Science Research (GSR) in collaboration with Cambridge Analytica.

The app offered payment in return for users filling out a personality test and Facebook says it was downloaded by 270,000 people.

The app also allegedly gave Mr Kogan access to the lists of the downloaders’ Facebook friends.

Cambridge Analytica's chief executive Alexander Nix has been suspended while Facebook founder Mark Zuckerberg has been called on to give evidence to MPs.

The judge told the court he will give his reasons for granting the application for the warrant on Tuesday.

Both Cambridge Analytica and Facebook deny any wrongdoing.

Mr Zuckerberg on Wednesday admitted the company "made mistakes" but said steps had been taken to protect users.

He says he is "open" to testifying before the US Congress on the scandal.