UPDATED March 1, 12:39 p.m. ET: The Verge reports that YouTube will no longer let videos featuring Momo host ads. This goes for news outlets reporting on it too, since YouTube has already said it's found no videos of the "Momo challenge" being promoted.

See original story below from 02/27/2019 below.

Kim Kardashian has taken up another cause: stopping the “Momo Challenge.”

The reality star took to her Instagram story on Wednesday to beg YouTube to shut down the challenge videos that have been popping up. The challenge calls for kids to self-harm and kill themselves. Kim reposted a handful of messages from worried parents who have heard of Momo.

However, YouTube told TMZ there’s no real proof that Momo clips exist—and if they are real then the videos would be a violation of the site’s policies, and would be removed right away. As a soon-to-be-mother-of-four, it makes sense Kim would be concerned about the challenge, though it’s unclear if her kids have seen a Momo video themselves.

CBS News reported on Wednesday that the challenge had recently resurfaced on WhatsApp in the U.K. The game gained international notoriety last summer and was initially thought to be a hoax, as it became a well-known meme. However, in August 2018, law enforcement looked into the influence of the challenge on the death of a 12-year-old in Argentina, which concerned parents around the world. CBS writes:

“When children participate in the challenge, they contact a stranger concealing themselves as Momo, using a creepy image and communicate primarily through… WhatsApp. Momo encourages a participant to complete various tasks if they want to avoid being ‘cursed.’ Some of the tasks include self-harm, which Momo asks the participant to provide photographic evidence in order to continue the game. Ultimately, the game ends with Momo telling the participant to take their own life and record it for social media.”

The original image of Momo comes from a sculpture titled Mother Bird by Japanese artist Keisuke Aisawa. There isn’t any evidence that Aisawa is tied to the deadly game.

While the viral challenge went dormant after some time, parents in the U.K. have found the game on WhatsApp, and embedded in animated videos for children on social media. “WhatsApp cares deeply about the safety of our users,” a WhatsApp spokesperson told CBS News. “It's easy to block any phone number and we encourage users to report problematic messages to us so we can take action.”

Whoever’s spearheading the challenge is also hacking children’s programs. “Challenges appear midway through Kids YouTube, Fortnight, Peppa pig to avoid detection by adults,” a school in England called Northcott Community Special School tweeted. “Please be vigilant with your child using IT, images are very disturbing.”

A YouTube spokesperson told CBS News, “Our Community Guidelines prohibit harmful and dangerous challenges, including promoting the Momo challenge, and we remove this content quickly when flagged to us.”