LONDON, U.K. - Claiming that paedophiles are misusing the website to target children, Mars and Lidl have pulled advertisements from YouTube.

The move by advertisers came amid revelations that tens of thousands of active predatory accounts exist on the platform and leave indecent comments on videos of children.

The reports based on investigations led by BBC News and The Times revealed that these paedophiles are using the website to target children and evading protection mechanisms.

On the eve of one of the biggest shopping days of the year, brands including Mars and Lidl, have stopped advertising on YouTube after they were alerted that they were appearing with videos exploited by paedophiles.

According to these reports, some videos are posted by paedophiles and many are innocently posted by youngsters.

Further, these investigations have revealed that some of the comments are said to be sexually explicit, while others reportedly encourage children posting the videos to perform sexual acts.

The journalist that led the investigation said that they spoke to people from the site's "trusted lager" scheme, who report inappropriate content or behaviour by users to YouTube employees.

BBC said that some of the volunteer moderators told them there could be "between 50,000 to 100,000 active predatory accounts still on the platform" while another told The Times journalists that there are "at least 50,000 active predators" on the website.

According to the report, along with trusted flaggers, YouTube also uses algorithms to identify inappropriate sexual or predatory comments.

The system is reporedly said to be failing to tackle the problem and paedophiles are continuing to comment on videos of children.

The Times report noted that adverts for several major international brands, including a global sportswear brand and food and drink giants, appear alongside the videos.

The investigation has raised concerns that they could be indirectly funding child abuse.

In an official statement, Mars said, "We are shocked and appalled to see that our adverts have appeared alongside such exploitative and inappropriate content. It is in stark contrast to who we are and what we believe. We have taken the decision to immediately suspend all our online advertising on YouTube and Google globally. We have stringent guidelines and processes in place and are working with Google and our media buying agencies to understand what went wrong. Until we have confidence that appropriate safeguards are in place, we will not advertise on YouTube and Google."

Meanwhile, Lidl said, "We are extremely shocked and disturbed by the findings of this investigation and are grateful to have been informed about this. We have suspended all of our YouTube advertising with immediate effect. It is completely unacceptable that this content is available to view, and it is, therefore, clear that the strict policies which Google has assured us were in place to tackle offensive content are ineffective."

Following the investigation, YouTube issued a statement saying it had noticed a growing trend around content "that attempts to pass as family-friendly, but is clearly not" in recent months and announced new ways it was "toughening our approach."

In a blog post, Johanna Wright, vice president of product management at YouTube, said, "We have historically used a combination of automated systems and human flagging and review to remove inappropriate sexual or predatory comments on videos featuring minors. Comments of this nature are abhorrent and we work... to report illegal behaviour to law enforcement. Starting this week we will begin taking an even more aggressive stance by turning off all comments on videos of minors where we see these types of comments."