Nikola, the embattled electric vehicle start-up, has forced the removal of several critical videos from youtube, saying they infringed its copyright by using footage from the company including the now-famous clip of a prototype truck rolling down a hill.

At least two online financial commentators who run channels on the google-owned video platform have had clips removed by youtube this week.

Sam alexander, who runs a youtube account that has posted several critical videos about nikola, said he received a notification from the platform on wednesday afternoon that one of his videos had been taken down because he had used footage of the nikola one truck in motion.

He added that 10 minutes later, another three of his videos with the same footage were removed.

Right now my main concern is that nikola is using copyright strikes to silence their critics, he told the financial times, adding that he was considering filing an appeal with youtube.

A spokesman for nikola said: youtube regularly identifies copyright violations of nikola content and shares the lists of videos with us. based on youtubes information, our initial action was to submit takedown requests to remove the content that was used without our permission. going forward, we will evaluate these flagged videos on a case-by-case basis.

The short clip of the nikola one seemingly driving along a deserted highway became a lightning rod for critics who argued the company had been overselling its technological achievements. a report from the short seller hindenburg research used it as evidence that the company was an intricate fraud.

Nikola, which has called the report misleading, did admit that the vehicle was rolling rather than driving, arguing it only ever said the truck was in motion.

Since its flotation earlier this year, nikolas shares have been heavily traded and highly volatile, as an army of retail investors debated its prospects. less than two weeks after hindenburgs report, founder trevor milton stepped down, and the company has been trying to get back on the front foot.

On wednesday, it cancelled its flagship product showcase day but reaffirmed key production timelines in an attempt to reset expectations around the business.

Youtubes copyright rules state that in the us, works of commentary, criticism, research, teaching, or news reporting might be considered fair use, but it can depend on the situation.

Under the platforms copyright protection system, any youtube user is able to flag a video they believe infringes copyright. the clip is taken down, and the account that posted it is issued with a strike.

Three strikes leads to an account being permanently deleted and the user being banned from creating any new channels.

A youtube account holder who calls himself tom nash, who has attracted 41,000 subscribers to his financial commentary, was required to take down three videos that featured criticism of nikola, including one that used footage of the rolling truck. the infringement cited on mr nashs videos related to footage of its prototype jet skis and a hydrogen station. he has appealed against the decision.

Its what you would call a death sentence for a creator, the user known as mr nash told the financial times. this is my livelihood. i have three kids. i quit my job to do this.

Both mr nash and mr alexander claimed that nikola was seeking to censor their videos for criticising the company. some youtube accounts that include the clip of the nikola one are still online, including a news report from yahoo finance.

While the company has removed the video from its own website, on thursday evening in the united kingdom the clip was still posted on the companys twitter account and on its youtube channel.

Youtube did not respond to a request for comment.

Additional reporting by hannah murphy in san francisco