Facebook has suspended the accounts of five people for spreading disinformation during Alabama’s 2017 special election – including the chief executive of a top social media research firm, which helped the US government discover how Russia used social media to share fake news during the 2016 presidential election.

“We take a strong stand against people or organisations that create networks of accounts to mislead others about who they are or what they’re doing,” Facebook told The Washington Post. “We’ve removed thousands of Pages, Groups and accounts for this kind of behaviour, as well as accounts that were violating our policies on spam and coordinated inauthentic behaviour during the Alabama special election last year.”

Jonathon Morgan, CEO of New Knowledge, previously told The Washington Post that he had created a misleading Facebook page to appeal to conservatives and purchased retweets on Twitter to measure the potential ‘lift’ of political messages, as part of an experiment looking at misleading online tactics during the 2017 election involving Republican Roy Moore and the since-elected Democratic Senator Doug Jones.

Morgan is adamant that he had been acting as a researcher trying to gain a better understanding of how the spread of online disinformation works and it was not his intention to have any impact on the election. However, his efforts coincided with a campaign aimed at undermining Moore’s candidacy, which was reported by the New York Times.

In a statement on Twitter, Morgan said: “My involvement in the project described in the New York Times was as a cyber-security researcher and expert with the intention to better understand and report on the tactics and effects of social media disinformation. I did not participate in any campaign to influence the public and any characterisation to the contrary misrepresents the research goals, methods and outcome of the project.”

Facebook has said that its investigation has not found that any accounts or pages directly operated by New Knowledge have violated any of its policies.