Advertisements from over 300 major companies ran on Youtube channels promoting extremist, white nationalist or other offensive content, according to a CNN investigation.

Companies such as Facebook, Mozilla, Nordstrom, Facebook, Linkedin, Amazon, Casio, Hilton and Hershey unintentionally helped finance some of the channels that promote white nationalists, Nazis, conspiracy theories, paedophilia, North Korean propaganda and other things via advertisements they paid for on world’s most popular video-sharing website.

Besides tech firms, media outlets, social media platforms and online retailers, ads from U.S government agencies, including Centers for Diseases Control and Department of Transportation also appeared on these channels, the investigation found.

YouTube has come under fire several times in recent months over the presence of videos that included hate speech and extremist content on its platform.

Besides tech firms, media outlets, social media platforms and online retailers, ads from five U.S government agencies also appeared on controversial channels

Last month, the website found itself in another controversy after allowing controversial channels to monetize their videos. As a result of the move, several major companies paused their ads on the platform.

One of these companies is Under Armour, whose ads appeared on a white nationalist channel – “Wife With A Purpose.”

Similarly, 20th Century Fox said on Friday that its ads appeared on videos posted by a “self-described Nazi,”, even when all appropriate filters were in place.

Several other major companies, including McDonald’s, PepsiCo and Johnson and Johnson have already scaled back their ads from the YouTube.

According to Fortune, the growing ad boycott by brands could cost website’s parent company Google around $750 million in revenue.

Brands advertise on YouTube to reach more and more targeted audience.

According to YouTube, it has more than one billion users who watch a billion hours of videos every day.

“We have partnered with our advertisers to make significant changes to how we approach monetization on YouTube with stricter policies, better controls and greater transparency,” a YouTube spokeswoman said.

“When we find that ads mistakenly ran against content that doesn’t comply with our policies, we immediately remove those ads. We know that even when videos meet our advertiser friendly guidelines, not all videos will be appropriate for all brands. But we are committed to working with our advertisers and getting this right,” she added.