Facebook investigated suspicions of Russian data harvesting as early as 2014, at least two years before the social network admitted to widespread interference from Moscow, according to private emails seized by Parliament.

Damian Collins, the chairman of the Commons Digital, Culture, Media and Sport Committee, revealed that Facebook staff had found computers in Russia accessing “3bn data points a day” from the social network in 2014.

Facebook said it had investigated the matter and found that it did not constitute genuine interference from Russia. It said the internet traffic being sent to Russia was legitimate, and related to Pinterest, a popular picture sharing app.

However, the disclosure raises more questions about how Facebook dealt with Russian attempts to interfere with the service. The Kremlin has been accused of meddling with democratic votes in the US, UK and elsewhere in Europe, and Facebook has previously said it did not discover any such attempts until after the 2016 Presidential election.

At a hearing of an “international grand committee on disinformation and fake news”, a coalition of different parliamentary committees investigating Facebook, Mr Collins asked the social network’s European policy chief Richard Allan why the investigation was not previously disclosed.