Nearly a quarter of men surveyed in six Asia-Pacific countries admit to committing rape, often against their own partners, according to a UN report published Tuesday that exposes widespread violence against women.
Based on anonymous interviews with more than 10,000 men aged between 18 and 49-years-old in Bangladesh, China, Cambodia, Indonesia, Sri Lanka and Papua New Guinea, the study is the first of its scale in the region.
"Violence against women is a harsh reality for many," Roberta Clarke, regional director of UN Women, said at the launch of the report in Bangkok.
"We must change the culture that enables men to enact power and control over women."
The prevalence of rape varied widely between locations, the UN said, explaining that its sample areas were not representative of whole countries.
Using a definition of non-consensual, penetrative sex as a benchmark, the study said 11 percent of respondents reported having raped a woman who was not their partner.
This rose to nearly a quarter -- 24 percent -- when their partner was included in the question.
Of those men who said they had committed rape, just under half (45 percent) said they had raped more than one woman.
Alarmingly, of those who admitted rape, half were teenagers and 12 percent were younger than 15-years-old, while the majority of men surveyed said they had not faced any legal consequences for their actions.
The highest prevalence (more than 62 percent) of rape was found in Bougainville, in Papua New Guinea, where a decade of war ravaged the island until 1998 and community justice is often favoured over legal process.
In the restive neighbouring Indonesian province of Papua the rates were at nearly 49 percent, while 26 percent of respondents in Jakarta admitted to the crime.
Rates in the one Chinese area surveyed reached 22 percent while those in Cambodia -- the most comprehensively studied with respondents drawn from five districts -- were at 20 percent, the report found.
The probe is not intended to be an authoritative statistical overview of rape in these six countries or of the Asia-Pacific region, say the authors.
"Violence is pervasive but it is also preventable," according to report researcher Emma Fulu of Partners for Prevention.
"The factors we found associated with violence are changeable," she said, citing high rates of child abuse, recent conflicts shredding social structures and poor law enforcement.
In addition, men who had witnessed violence against their mothers or frequently paid for sex were more likely to continue the cycle of violence, she added.
To break the pattern young people should be engaged with issues "around what consent means... understanding sexuality and masculinity" within relationships, Fulu added.
The study was released on the same day that a court in India found four men guilty of gang-raping and murdering a student on a bus last December.
Her shocking death turned a spotlight on sexual violence, raising questions about what can prompt some men to accept rape or perpetrate it themselves.
Until now, such research has depended mainly on crime reports, which may be sketchy or skewed, or on accounts by women rather than by men.
Taking a new approach, trained male researchers held lengthy one-to-one interviews with men in cities and the countryside, with the respondents gaining a guarantee of anonymity.
The respondents were not asked directly whether they had committed rape, but instead were asked questions such as "Have you ever forced a woman who was not your wife or girlfriend at the time to have sex?" or "Have you ever had sex with a woman who was too drugged or drunk to indicate whether she wanted it?"
They were also asked why they had done so.
Nearly three-quarters of respondents indicated reasons of sexual entitlement, saying for example, "I wanted her" or "I wanted to have sex."
Fifty-nine percent did it for entertainment, while more than a third -- 38 percent -- said they had raped a woman to punish her.