Videos showing kids how to kill themselves have been found on Google's YouTube Kids app.
CBS News reports at least two have been featured on the supposedly child-friendly app since July, discovered by a paediatrician in the US.
A man in one of the videos is a YouTuber known as Filthy Frank who has more than six million subscribers and calls himself "the embodiment of everything a person should not be".
In the clip he's seen making cutting motions on his arm, telling viewers to "end it" and explaining the best way to ensure a suicide attempt works, CBS News reports. The clip was edited to appear in the middle of a kids' cartoon.
"Looking at the comments, it had been up for a while, and people had even reported it eight months prior," Florida paediatrician Free Hess said.
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After she blogged about it, YouTube removed the clip. It's not clear if Filthy Frank knew his clip had been used in the offending video. It was originally a part of a video about a One Direction fan committing suicide.
Another version of the same clip was spotted last year, but reportedly wasn't removed until a parent directly contacted a Google employee.
The controversy comes a year after Google had to scrub the YouTube Kids app clean of disturbing 'Elsagate' videos, which often featured people dressed as popular cartoon characters taking part in violent and sexual activities.
"Once you start looking into it, things get darker and weirder," said Dr Hess. "I don't understand how it's not getting caught."
Videos that appear on YouTube kids are chosen by both algorithms and humans, but parents are able to block videos and channels that haven't been reviewed by a human.
"The very fact that these videos are still there, and can be watched, shows that Google and YouTube are not doing enough to safeguard kids," a spokesperson for the UK National Society for the Prevention of Cruelty to Children told The Sun.
Where to find help and support:
- Need to Talk? - Call or text 1737
- Lifeline - 0800 543 354 or (09) 5222 999 within Auckland
- Youthline - 0800 376 633, text 234, email email@example.com or online chat
- Samaritans - 0800 726 666
- Depression Helpline - 0800 111 757
- Suicide Crisis Helpline - 0508 828 865 (0508 TAUTOKO)