A pro-Scottish independence Facebook page has been removed after it was found to be a fake account set up in Iran.

The page, which was called Free Scotland 2014 and had more than 20,000 followers, was among 652 accounts taken down by the social media giant in its largest purge.

The Iranian-backed account was one of the most popular on the social media site devoted to Scottish independence.

It was also among a string of bogus pages which connected to fake “news” sites, including Quest 4 Truth which is linked to Iran’s main propaganda source, Press TV.

Free Scotland 2014 was discovered after Facebook security teams launched fresh investigations into fake accounts last August ahead of US mid-term elections.

Its posts included an apparent story in which former White House chief strategist Steve Bannon called for Boris Johnson to challenge Prime Minister Teresa May for her job, and another depicting The Queen and the Duke of Edinburgh discussing a hefty pay rise paid for by “the poor, the sick and the disabled”.

Facebook announced it had carried out a wide-ranging clear-out of Russian and Iranian-backed bogus pages at the same time as social media rival Twitter confirmed it had shut down 284 fake accounts for “engaging in coordinated manipulation”.

A statement on Twitter added that many of the accounts originated in Iran.

The Facebook pages included a network of accounts that promoted left-wing and anti-Western opinions, including some that posted in support of Labour leader Jeremy Corbyn and were specifically targeted at British voters.

Together they attracted almost one million followers.

Some of the pages paid almost £10,000 to Facebook to ensure they would appear on the timelines of other users even though they had not signed up to see them.

The purge, announced by Facebook’s head of cybersecurity policy Nathaniel Gleicher, shows Russia is not alone in using social media to adopt disguised sites to push its own political agendas.

Conservative MP Damian Collins, chairman of the parliamentary fake news inquiry, said the removal of the pages "was the tip of the iceberg".

He also called for greater transparency from Facebook.

“They’ve found a few hundred here or there targeting the UK and US and there were 30,000 removed close to the French election, but my concern is that this would be the tip of the iceberg,” Mr Collins said.

An internal investigation by the world’s biggest social network found four groups across Facebook and Instagram which spent thousands of pounds on advertising and had hundreds of thousands of followers.

The activity, some of which dates back to 2011, included spreading political messages and attempting to hack other people’s accounts or spread malware.

Writing on Facebook's blog, Mr Gleicher said: “We’ve removed 652 pages, groups and accounts for coordinated inauthentic behaviour that originated in Iran and targeted people across internet services in the Middle East, Latin America, UK and US.”

Separate activity from Russia which targeted politics in Syria and Ukraine was also removed, he said.

Pages called The British Left and Free Scotland 2014 shared posts about Jeremy Corbyn, Brexit, Boris Johnson and the Queen while others discussed Donald Trump’s presidency and the Israel-Palestinian conflict. Mr Collins said: “Users should also know whether the person operating the page is deliberately hiding their identity.”

Facebook increased transparency around the history of certain pages and political advertising earlier this year after whistleblowers revealed Russian agents and controversial data firm Cambridge Analytica targeted voters during the 2016 US election and the Brexit vote.

In July, the Electoral Commission fined official Brexit campaign group Vote Leave and reported senior figures to the police for breaking electoral law with Facebook adverts.