Facebook has admitted that up to 270m accounts on the social network are illegitimate, raising questions over the social network's integrity as it is under pressure over Russian meddling in elections across the world.
Buried in the social network's results on Wednesday night, it disclosed that there are tens of millions more fake and duplicate accounts than it had previously thought.
Around 2-3pc of its 2.1bn monthly users in the third quarter of 2017 were "user-misclassified and undesirable accounts", Facebook said, up from the 1pc it had estimated in July.
Another 10pc of its accounts are duplicates of real users, almost doubling its estimate of 6pc from last quarter's results. This suggests that in total, up to 13pc of its 2.1bn monthly users - almost 270m accounts - are illegitimate.
The company made the revelation in the small print of its earnings presentation, during which it unveiled a 79pc increase in quarterly profits to $4.7bn (£3.6bn).
It said that improvements to the data is used to identify fake accounts was behind the increase, rather than a sudden surge in fake users, although the company added that there may have been "episodic spikes", particularly in countries like Indonesia and Vietnam.
Facebook, which requires users to use their real names and in some cases prove their identity, has sought to position itself as being less polluted than other social networks, such as Twitter.
Fake accounts include those for businesses and organisations mistakenly set up as profiles, rather than pages, but also those purposefully set up for spamming and other activity banned by Facebook.
The disclosure, first reported by Business Insider, could lead to increased scrutiny of the social network as it is under pressure to reveal how fake news and politically charged advertising may have affected last year's US election as well as democracy around the world.
On Wednesday a US senator claimed that Russian operatives had "set up shop" in Scotland in an attempt to foment support for a second independence referendum as part of a global campaign of disruption. Facebook has admitted that 126m users in the US saw adverts funded by Russia, and another 20m on Instagram.
Facebook has previously had to revise its figures on key statistics, such as the average time people spend watching videos and the number of times users see advertisers' posts.
Its user numbers were also brought into question after it claimed that it reaches more people between the ages of 18 to 24 in the US than census data say exist.
Mark Zuckerberg, Facebook's chief executive, said on Wednesday night that the company's efforts to rein in abuse are likely to hit the company's profitability in the future.
Source: The Telegraph