The White House has shared digitally manipulated footage of a CNN reporter's interaction with an intern, according to an expert consulted by The Telegraph.
Sarah Sanders, the White House press secretary, shared C-Span footage of CNN reporter Jim Acosta and a White House intern, accusing him of placing his hands on her and using it as justification to remove Mr Acosta's press credentials.
The footage of C-Span's broadcast had earlier appeared on the Twitter account of Paul Joseph Watson, an editor for the alt-right conspiracy theorist website InfoWars when it was shared by Mrs Sanders.
The Telegraph asked a video verification expert to analyse the footage, who said it appeared to have been manipulated - you can watch our side-by-side comparison and analysis of the two videos below.
Experts said that in Mrs Sanders's version, the footage has been frozen for three frames to make the contact with the intern's arm longer and by implication more aggressive.
This is achieved by repeating the frames so fast the human eye cannot detect it.
Alan O'Riordan, a video verification expert, said there were clear "discrepancies" between the C-Span version and the version that Sarah Sanders tweeted.
"In [Mrs Sanders's] version, what we see is something that has been added to the original, it repeats several frames at a crucial moment of the footage basically," he said.
"We found three repeated frames where you can see Jim Acosta's arm make contact with the intern's arm."
Mr O'Riordan said he had done a side-by-side analysis of the two videos as well as a frame-by frame analysis to reach his conclusion.
The White House has not yet responded to requests for comment and we cannot be sure Mrs Sanders's footage is taken from InfoWars.
However Mr O'Riordan claimed Mrs Sanders's video "has the same features" as the InfoWars footage.
Mr Watson, of InfoWars, has denied claims the footage was doctored or sped up, saying he "merely zoomed in".
Mr O'Riordan has disputed that, saying: "Our analysis of the video clearly showed that the version tweeted by Paul Joseph Watson and by the Press Secretary had three frames that were repeated, at the point of contact. That version of the video was not "sped up" as has been suggested, but it was modified.
"The video was clearly manipulated, but I cannot say by whom."
The row began after a press conference on Wednesday, during which a White House intern tried to physically remove Mr Acosta's microphone as he repeatedly questioned the president.
Mrs Sanders released a statement accusing Mr Acosta of "placing his hands on a young woman just trying to do her job as a White House intern", calling it "absolutely unacceptable".
The interaction between Mr Acosta and the intern was brief, and Mr Acosta appeared to brush her arm as she reached for the microphone and he tried to hold on to it. "Pardon me, ma'am," he told her.
Mr Acosta called Mrs Sanders's characterisation of the incident "a lie", and CNN released a statement defending its reporter.
The cable news network claimed the White House revoked Mr Acosta's press pass out of "retaliation for his challenging questions".
Journalists assigned to cover the White House apply for passes that allow them daily access to press areas in the West Wing.
White House staffers decide whether journalists are eligible, though the Secret Service determines whether their applications are approved.
Mr Acosta's press pass was revoked by the White House following his heated exchange with President Trump, who called him a "rude, terrible person".
The episode will reignite fears that Mr Trump has scant regard for press freedom and is intent on limiting space for critical coverage.
During his angry exchange, Mr Trump told the reporter "CNN should be ashamed of itself having you working for them" and told him to put the microphone down.
"You are a rude terrible person," Mr Trump added. "The way you treat [White House press secretary] Sarah Huckabee is horrible... You shouldn't treat people that way."
Mr Acosta persevered in his attempt to question the president, but Mr Trump told him: "That's enough. Put down the mic."
Journalists and politicians have rallied to defend Mr Acosta, with the White House Correspondents' Association saying it "strongly objects" to the decision to revoke his press pass.
The Association's president, Olivier Knox, called it "a reaction out of line to the purported offence".
"Journalists may use a range of approaches to carry out their jobs and the WHCA does not police the tone or frequency of the questions its members ask of powerful senior government officials, including the President," he wrote.
Meanwhile Jeb Bush, Republican politician and brother of President George W Bush, said: "The media is not the enemy of the people. The freedom of the press is protected by the Constitution. Presidents never enjoy pointed questions from the press, but President Trump should respect their right to ask them and respect Americans enough to answer them."
CNN claimed Mrs Sanders "provided fraudulent accusations and cited an incident that never happened. This unprecedented decision is a threat to our democracy and the country deserves better".
It added: "Jim Acosta has our full support."