White House press secretary Sarah Huckabee Sanders has been accused of sharing a video doctored to make a journalist appear more aggressive.
The clip shows the moment CNN reporter Jim Acosta refused to hand over a microphone to an intern during a heated news conference with US President Donald Trump.
The White House has since banned Mr Acosta over what it called “unacceptable” conduct.
Ms Sanders took aim at the CNN correspondent after accusing him of “placing his hands on a young woman just trying to do her job as a White House intern”.
Ms Sanders went on to share a clip published by cable network C-SPAN, writing: “We stand by our decision to revoke this individual’s hard pass. We will not tolerate the inappropriate behavior clearly documented in this video.”
But Storyful, a social media intelligence agency that specialises in video, say its analysis shows the clip “contains extra frames that do not appear in the C-SPAN broadcast of the event”.
Its report claims the video has several frames repeated.
It says: “These frames do not appear in the original C-SPAN footage, and appear to exaggerate the action of Acosta.”
Many furiously criticised Ms Sanders for sharing the video, including one of Mr Acosta’s colleagues.
Matt Dornic, a vice-president at CNN, said: “Absolutely shameful, @PressSec. You released a doctored video – actual fake news. History will not be kind to you.”
The Storyful report also says: “The video shared by Sanders appeared under an hour after the same video, with the same close-up, was posted by Infowars.com contributor Paul Joseph Watson.”
Infowars.com is a controversial far-right site described by many as a publisher of conspiracy theories and fake news.
Storyful say when it compared the video posted by Mr Watson side-by-side with the C-SPAN footage “there is a clear moment (frames 13, 14, 15 in our first clip, where C-SPAN version is on the left) when the Sanders video halts and the C-SPAN footage does not.
“The two clips, which were roughly in sync before that moment, are out of sync thereafter,” Storyful said.
The same three still frames are repeated in the zoomed-in clips of the incident in the Sanders video, its report adds.
Mr Watson posted his defence on Twitter, saying: “Here’s the video that proves I did not ‘doctor’ or ‘speed up’ the Acosta video, as some media outlets claim. I merely zoomed in.
Here’s the video that proves I did not “doctor” or “speed up” the Acosta video, as some media outlets claim. I merely zoomed in.
Nice try to distract from Acosta’s behavior, but this kind of dishonesty is why the media has a massive trust issue.
Please correct your stories. pic.twitter.com/g0AzlEyVx0
— Paul Joseph Watson (@PrisonPlanet) November 8, 2018
“Nice try to distract from Acosta’s behavior, but this kind of dishonesty is why the media has a massive trust issue.
Both the C-SPAN video and the footage posted by Ms Sanders were set to play at 29.97 frames, as was the software suite we used to do this analysis, eliminating the possibility that the error was caused when the footage was imported into editing software by Storyful.