A UK privacy watchdog is assessing how personal data may have been used and exploited for political purposes during the British referendum to leave the EU in 2016.

The Information Commissioner’s Office (ICO) is investigating claims that Cambridge Analytica, the data analytics company, helped to aid the Leave campaign by identifying key swing voters on Facebook, but did not declare this assistance to the electoral commission.

The analytics company uses personal data to construct profiles on people and how they might vote, having previously claimed responsibility for the result of the US elections last year. However, in Europe political campaigns are not permitted to use third party data without consent.

Brexit choke hold

An ICO spokeswoman said: “We are conducting a wide assessment of the data-protection risks arising from the use of data analytics, including for political purposes, and will be contacting a range of organisations.”

“We intend to publicise our findings later this year.”

The company is reportedly part owned by US hedge fund Billionaire, Robert Mercer, a friend of Nigel Farage, one of the owners of far right publication Breitbart, and a financial backer of Donald Trump.

Stephen Kinnock, Labour MP and Remain supporter, asked the Electoral Commission to investigate the allegations on Friday following the report in The Observer.

Cambridge Analytica deny any work either paid or unpaid that benefited the Leave campaign and a spokesman told The Observer: “We are in touch with the ICO, and are happy to demonstrate that we are completely compliant with UK and EU data law.”

Caroline Lucas, Green MP and Remain supporter, said: “Clearly, there are questions to be answered about the Leave campaign’s use of big data and a potentially huge ‘in kind’ donation by Cambridge Analytica. To have a foreign billionaire’s fingerprints left all over such a seismic moment in British history is deeply concerning and requires urgent further investigation as to whether electoral law was broken.”