Seventy percent of children in Papua New Guinea suffer physical abuse and 50% face family violence, a new report has found.
The study by Save the Children, UNICEF and Doctors without Borders found children in PNG face high levels of abuse, neglect and exploitation.
Save the Children's country director for PNG, Jennifer El-Sibai, said the findings were "very concerning".
"The research suggests that sexual violence against children primarily happens within the home, which is very concerning — or at least within the extended family unit," she said.
"Certainly, children are also facing really high levels of physical violence, of neglect and exploitation — and that's happening outside the home as well.
"Unfortunately it seems to be an issue at every sort of strata of the community at the moment."
The report found many communities will only report very serious incidents of abuse.
"By really serious, they are talking about rape," Ms El-Sibai said.
"It goes back to parents not necessarily understanding the impact of all forms of violence on their children and how to support them."
Ms El-Sibai said because there was no national data, the findings were based on small-scale studies.
"To be perfectly honest, while the numbers are very high and certainly that's the case with physical and sexual violence, it's potentially the issue that the problem of neglect, exploitation and of other forms of abuse may even be higher, because we just don't hear the cases being reported through to the formal system," she said.
Papua New Guinea's rates of violence are described as at "pandemic" levels, with almost two-thirds of women facing domestic violence.
She is calling for a more formal reporting system to ensure the scale of the issue is accurately gauged.
"We actually need a management information system, whereby we can actually determine what the scale of the problem is," she said.
There are fears widespread abuse could have a long-term effect on many within Papua New Guinea's next generation.
"Often people only think about the immediate emotional or physical consequences to a child that's been exposed to violence, but more and more the research is telling us it actually has long-reaching effects," Ms El-Sibai said.
"Not just throughout childhood, but even into adulthood."
The report backs up findings by Doctors Without Borders, which released a separate report earlier this year.
The report showed women and children endure shockingly high levels of family and sexual violence, with rates of abuse estimated to be some of the highest in the world outside a conflict zone.
Doctors Without Borders said it had treated 27,993 survivors of family and sexual violence in the country since 2007.
However, there is hope the problem will improve.
"There has been a remarkable amount of momentum and commitment given to the issue, especially in the last three years," Ms El-Sibai said.
"In 2015 the Papua New Guinean Government legislated the latest child protection framework...which is a huge step in the right direction.
"Certainly when you hear on the ground, speaking to people who have worked in social welfare and social protection, there are a great many people who are committed to addressing the issue."
However Ms El-Sibai said more needs to be done.
"What we are calling for is to address the issue with those that are part of the family and the community fabric," she said.
"As important as it is to put resources into crisis response services, not enough is being done to address the issue of prevention or identifying really early on kids that might be at risk."