Fox News anchor Sandra Smith was caught reacting incredulously to a guest casting doubt over the legitimacy of Joe Biden’s election win over the weekend, frowning and rolling her eyes while she was off-air.

In a leaked clip circulating online, the host of America’s Newsroom was heard exasperatedly asking ‘what is happening’ as DC-based lawyer Cleta Mitchell repeated Donald Trump’s unfounded accusations of widespread election fraud.

‘I think everybody wants to know that this was done properly and legally and we can trust the results,’ Mitchell, who was being interviewed by Fox News’ Trace Gallagher, said. ‘And I think we have to look into every one of these concerns.

‘Remember, just because CNN says, or even Fox News says that somebody’s president doesn’t make them president,’ Mitchell continued.

In a clip circulating online, the host of America’s Newsroom was heard exasperatedly asking ‘what is happening’ as DC-based lawyer Cleta Mitchell (shown center left) repeated Donald Trump’s unfounded accusations of widespread election fraud

In a clip circulating online, the host of America’s Newsroom was heard exasperatedly asking ‘what is happening’ as DC-based lawyer Cleta Mitchell (shown center left) repeated Donald Trump’s unfounded accusations of widespread election fraud

While Mitchell was speaking, Smith, who was not on air at the time, could be seen rolling her eyes, furrowing her brow and shaking her head.

One of Smith's many animated reactions is captured in the above image

While Mitchell was speaking, Smith, who was not on air at the time, could be seen rolling her eyes, furrowing her brow and shaking her head.

While Mitchell was speaking, Smith, who was not on air at the time, could be seen rolling her eyes, furrowing her brow and shaking her head.

‘What?’ Smith said, looking up in disbelief and appearing to be unaware that she was being picked up on a hot mic.

While Mitchell continues speaking, Smith then interjects in an angrier tone, ‘What is happening? Like, Trace, we’ve called it.’

Gallagher, meanwhile, simply replied to the lawyer, ‘Yeah. I think that’s a good point there,’ and moved the conversation over to another guest, Steve Mulroy, a law professor at University of Memphis.

The video was first circulated on Twitter by political consultant, and former Daily Beast director of video, Timothy Burke.

‘Sandra Smith, off-air, reacts to her colleague Trace Gallagher indulging a nutjob who denies the outcome of the election even after Fox News had called it for Joe Biden,’ Burke wrote in his post.

It’s currently unclear how the clip came to emerge on social media. Fox News has not yet responded to a DailyMail.com request for comment on the matter.

Smith, who first joined Fox Business Network as a reporter in October 2007, is a regular foil of White House spokespeople and has a back catalogue of viral clips showing her clashing with members of the Trump administration, including the likes of Kellyanne Conway.

‘What?’ Smith said, looking up in disbelief and appearing to be unaware that she was being picked up on a hot mic

While Mitchell continues speaking, Smith then interjects in an angrier tone, ‘What is happening? Like, Trace, we've called it.’

‘What?’ Smith said, looking up in disbelief and appearing to be unaware that she was being picked up on a hot mic. While Mitchell continues speaking, Smith then interjects in an angrier tone, ‘What is happening? Like, Trace, we’ve called it.’

Mitchell (left) was either unable to hear Smith or chose to ignore her heckles, as she continued speaking without wavering

Mitchell (left) was either unable to hear Smith or chose to ignore her heckles, as she continued speaking without wavering

During an August interview, Conway, the counsellor to the president, falsely claimed that Biden has no plan in place for the coronavirus pandemic, despite having published one on his website.

Smith repeatedly corrected Conway throughout the interview, which took place after the second night of the Democratic National Convention.

‘I thought the most remarkable part of the evening — apart from Joe Biden, who seems like a very nice person — I thought the most remarkable part of the evening was AOC making her one minute count by endorsing — actually nominating — Bernie Sanders for president,’ Conway said, referring to Rep. Alexandria Ocasio-Cortez’s brief address.

‘AOC, Bernie, Elizabeth Warren — they’ve got a lot of power over the platform and they will have a ton of power over a Biden presidency,’ concluded President Donald Trump’s one-time campaign manager.

Smith responded: ‘To be clear, that’s been reported as a lack of endorsement on her part for Joe Biden. She has asked for clarification from other news outlets this morning — not us — saying that that wasn’t the case. She didn’t mention Joe Biden’s name last night, but she does support Joe Biden. She put that out there this morning.’

During another exchange, Conway said she didn’t hear any Democrats talk about a plan to combat the coronavirus, to which Smith resolutely responded, ‘He’s got a plan. Joe Biden’s got a plan.’

‘Oh yeah? Where is it?’ asked Conway.

‘It’s on his campaign website,’ replied the anchor, to which Conway responded: ‘Yeah, sure.’

During an August interview, Conway, the counsellor to the president, falsely claimed that Biden has no plan in place for the coronavirus pandemic, despite having published one on his website

During an August interview, Conway, the counsellor to the president, falsely claimed that Biden has no plan in place for the coronavirus pandemic, despite having published one on his website

On the Monday before the election, Smith also got in a skirmish with former White House director of communications, Anthony Scaramucci as the two continually talked over one another on the former Trump operative supporting Mr Biden’s economic policies.

‘You’re not letting me talk,’ Scaramucci said. ‘You brought me on here to be a crash dummy.’

Trump is reportedly considering holding a campaign-rally style tour in a number of battleground states where he will be filing lawsuits and contesting the vote counts that propelled Biden to the White House, including Pennsylvania.

Contrary to Trump’s claims, there is no evidence of widespread voter fraud or election fraud.

Moreover, none of the lawsuits filed by his campaign has alleged voter fraud, focusing instead on delaying ballot counting or discarding a small number of ballots in states that would have no effect on the final result because of Biden’s margin of victory.