Facebook prematurely turned off safeguards designed to thwart misinformation after Joe Biden defeated Donald Trump in last year's elections in a moneymaking move, a whistleblower claims.

The whistleblower, former Facebook product manager Frances Haugen, said this contributed to the invasion of the US Capitol on January 6.

She also asserted during an exclusive interview that aired Sunday on CBS' 60 Minutes that a 2018 change to the content flow in Facebook's news feeds contributed to more divisiveness and ill will in a network ostensibly created to bring people closer together.

Despite the enmity that the new algorithms were feeding, Facebook found that they helped keep people coming back - a pattern that helped the Menlo Park, California, company sell more of the digital ads that generate most of its advertising.

She said: "The thing I saw at Facebook over and over again was there were conflicts of interest between what was good for the public and what was good for Facebook.

"And Facebook, over and over again, chose to optimise for its own interests, like making more money."

Facebook's annual revenue has more than doubled from 56 billion dollars (£41.4 billion) in 2018 to a projected 119 billion (£88 billion) this year, based on the estimates of analysts surveyed by FactSet.

Meanwhile, the company's market value has soared from 375 billion dollars (£275 billion) at the end of 2018 to nearly 1 trillion dollars (£750 billion) now.

Even before the full interview came out, a top Facebook executive was deriding the whistleblower's allegations as "misleading".

Nick Clegg, the company's vice president of policy and public affairs wrote to Facebook employees in a memo sent on Friday, saying: "Social media has had a big impact on society in recent years, and Facebook is often a place where much of this debate plays out.

"But what evidence there is simply does not support the idea that Facebook, or social media more generally, is the primary cause of polarisation."

The 60 Minutes interview intensifies the spotlight already glaring on Facebook as politicians and regulators around the world scrutinise the social network's immense power to shape opinions and its polarising effects on society.

The backlash has been intensifying since The Wall Street Journal's mid-September publication of an expose that revealed Facebook's own internal research had concluded the social network's attention-seeking algorithms had helped foster political dissent and contributed to mental health and emotional problems among teenagers, especially girls.

After copying thousands of pages of Facebook's internal research, Ms Haugen leaked them to the Journal to provide the foundation for a succession of stories packaged as the Facebook Files.

Although Facebook asserted the Journal had cherry picked the most damaging information in the internal documents to cast the company in the worst possible light, the revelations prompted an indefinite delay in the rollout of a kids version of its popular app Instagram.

During the interview, Ms Haugen said: "No-one at Facebook is malevolent.

"But the incentives are misaligned, right? Like, Facebook makes more money when you consume more content.

"People enjoy engaging with things that elicit an emotional reaction. And the more anger that they get exposed to, the more they interact and the more they consume."