Communicating with the House of Commons' Digital, Culture, Media and Sport Committee, the online platform said it would examine whether there were more clusters of accounts spreading disinformation, having previously come under criticism for conducting a limited probe.
An independent investigation by the Guardian newspaper revealed that more than 400 bogus Twitter accounts run by the Russian agency have tried to meddle in British politics.
Facebook is reconsidering whether Russian operatives exploited its platform to influence Britain's so-called "Brexit" referendum on leaving the, Simon Milner, the social network's United Kingdom policy director, told a member of Parliament.
Yesterday its United Kingdom policy director Simon Milner wrote to a parliamentary committee that's been conducting a wide-ranging enquiry into fake news - and whose chair has been witheringly critical of Facebook and Twitter for failing to co-operate with requests for information and assistance on the topic of Brexit and Russian Federation - saying it will widen its investigation, per the committee's request.
Writing to Mr Collins, Mr Milner said: "You expressed a view that there may be other similar coordinated activity from Russian Federation that we had not yet identified through our investigation and asked for use to continue our investigatory work".More news: Messi misses penalty in defeat
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This is rather important information because it explains why he continues to pursue the Russia story even though his own government concluded earlier that it has found no evidence of successful Russian interference in the Brexit referendum.
The prominent Conservative MP has also previously criticised Twitter over its response to his committee's inquiry.
Facebook expands its investigation into possible Russian intervention in Brexit referendum after pressure from British authorities, who have been dissatisfied with a previous version of the study.
Facebook is set to widen its search for evidence of Russia's alleged interference in Britain's European Union referendum.
The social media company originally claimed it had only spent $1 on advertising towards voters in the United Kingdom, but Collins said the investigation did not go far enough as it didn't look at other sources.