Scott Morrison is demanding a graphic video circulating on social media platform TikTok be taken down.
Parents and children have been warned to be wary of footage showing a man in the United States taking his own life.
The video was originally posted to Facebook but is now circulating on TikTok.
Predators are reportedly using innocent clips of animals to lure children into watching the suicide video.
The prime minister said the laws and standards of behaviour for the real world must also apply online.
“No child should be exposed to horrifying content like this,” Mr Morrison said on Wednesday.
“Platforms like TikTok need to put in more resources to detect and tear down this sort of harmful content. That is their responsibility.”
Mr Morrison said Australia’s eSafety commissioner was engaging closely with TikTok to get the video removed.
A spokeswoman for TikTok said moderators were detecting and removing the video as people tried to upload it.
“We are banning accounts that repeatedly try to upload clips,” she told AAP.
“We appreciate our community members who’ve reported content and warned others against watching, engaging or sharing such videos.”
TikTok has also been accused of censoring political and social topics such as LGBTI issues and the crackdown in Uighurs in China.
A new report by the Australian Strategic Policy Institute describes the video-sharing platform as a powerful political actor with global reach.
It found the Chinese-owned company censored topics and suppressed content to make it harder to find.
According to TikTok, some of the terms ASPI highlighted were restricted due to local laws.
The company fixed an issue where some Arabic phrases were being incorrectly moderated, as well as another incident where English phrases were incorrectly screened.
“We believe that accountability and transparency are essential to facilitating trust with our community,” the spokeswoman said.
“As part of this, we’ve committed to making our moderation policies, algorithm, and data security practices available to experts, which no other company in our space has been willing to do.”
The spokeswoman said TikTok user data was stored in the US and Singapore with strict controls on employee access.
“We have never shared user information with the Chinese government, and wouldn’t do so if asked,” she said.
The prime minister has previously ruled out banning TikTok but said intelligence agencies would continue to monitor the popular short video app.