Women in poverty-stricken Papua New Guinea suffer "severe brutality" with violence, including savage attacks involving knives, axes and whips, occurring in two-thirds of all families, a new study revealed on Tuesday.

Based on interviews in Central Province's Rigo district, the report by Australian charity ChildFund detailed extreme acts of violence including a woman who had her lower lip bitten off by a stranger and one whose infant son's unconscious body was used as a weapon against her.

Although there was no official government data on violence against women and children in the rugged Pacific nation, ChildFund said it was widely reported to occur in two-thirds of PNG families and "the incidence is likely to be higher than two in three".

One study cited by the charity in its report found that half of all women would be raped in their lifetime, and another reported that 86 percent were beaten during pregnancy.

Of those seeking medical help after being raped, half were younger than 16, one quarter were younger than 12 and one in 10 were under eight years of age.

ChildFund interviewed 37 women in four villages and 14 men for the case studies used in the report.

"Most women interviewed during our field research in Rigo district, Central Province had experienced violence, and not one claimed to have a husband who had never beaten them," ChildFund said.

The case studies included a woman whose one-month-old baby was punched unconscious by her husband and his body used as a weapon against her. The baby survived the attack.

Another, Helen, had her lower lip bitten off in a random attack in the capital Port Moresby.

"Sometimes when I sleep, I dream he will come to me and I am really scared about it. I think he is coming back again," she said.

At the city's Family Support Centre, ChildFund said they saw women with chunks of skin, cheeks, noses and ears missing after violent biting attacks, as well as injuries from spears, bush knives or machetes and whips.

PNG's government enacted harsh new laws earlier this year making sexual and other crimes against women punishable by death after a spate of violence including the burning alive of a young mother accused of witchcraft, the beheading of another, and the rape of two foreigners.

Aid organisation Medecins Sans Frontieres (MSF) has labelled PNG's sexual and domestic violence a humanitarian crisis, with epidemic levels of abuse unique outside of a war-zone or state of civil unrest.

The group has said that violence is inherent in the way the population resolves disputes at a tribal, family and interpersonal level. The extremely low status of women in the country is also a factor.

PNG ranks 134 out of 148 countries in the 2012 UNDP Gender Inequality Index, and 156 out of 186 in the Human Development Index - the lowest in the Pacific.

Life expectancy is low, at 61 years for males and 65 for females. Infant mortality is high, and maternal mortality is the highest in the Pacific, among the highest in the world.

Currently, 37 percent of the population lives in poverty, and less than half of school-age children are enrolled in classes.

MSF estimates that 70 percent of women in PNG will be raped or physically assaulted in their lifetime.