A Facebook video that was altered to make House Speaker Nancy Pelosi seem drunk appears to have been removed from the social network. Who took down the video, which garnered millions of views and generated storms of controversy, is unclear. 

On Monday, Politics WatchDog, the group that posted the video to its Facebook Page, said the social network had removed the video. A Facebook spokeswoman refuted the allegation, saying, "We did not remove the video."

Politics WatchDog didn't say how it knew Facebook was responsible for the video's removal or if it had been informed of the action. The group, which says it polices both Republicans and Democrats, didn't immediately respond to a request for additional comment. 

CNET couldn't find the video, which was adjusted to make Pelosi appear to be slurring her words, on Politics WatchDog's Facebook Page. A link to the video in a previous CNET report redirected to the homepage for Facebook Watch, the social network's video streaming hub, suggesting the original post was no longer active. Another link to the video says the content isn't available: "The link you followed may have expired, or the page may only be visible to an audience you're not in."

Facebook didn't answer questions about whether the video was still in its system or if Politics WatchDog's administrators may have adjusted privacy settings to prevent it from being displayed publicly.

Facebook has weathered mounting criticism for keeping the video up. The video wasn't removed, Facebook said, because the social network doesn't have a policy requiring posts to be true. 

The video highlights the growing problem of fake news on social media. Facebook has come under particular fire from lawmakers, including conservatives who say the social network is censoring far right voices. The social media company says it's trying to combat misinformation while balancing safety and free expression.

Facebook doesn't have a rule that requires content posted on the site to be true. Its community standards state it doesn't remove fake news but will show it lower in its News Feed. However, the company has taken down fake accounts for "inauthentic behavior," which means the people behind the accounts tried to mislead users about who they were and what they were doing. 

The doctored Pelosi video shows the California Democrat speaking at a Center for American Progress event in May. The speed of the video was slowed down and the pitch of the politician's voice was altered. During the speech, Pelosi accused President Donald Trump of being part of a "cover-up."

The video was originally posted on May 22 at 10:29 a.m. As of May 31, it had garnered 2.9 million views and more than 48,700 people shared it. Fact-checker Lead Stories said in an analysis last week that after the video was rated as false, the average amount of shares, likes and views to the video decreased. 

Critics have called out Facebook for not explicitly identifying the video as having been manipulated. Instead, Facebook directed users to fact-checkers that published articles about how the video footage was distorted. Lawmakers, including Pelosi, blasted the social network for leaving the video up. Pelosi's office didn't immediately respond to a request for comment on Monday night. 

Twitter also left the videos up but declined to comment. YouTube pulled the videos down, stating that it violated its policies against deceptive practices.