South Africa must end a culture of male dominance to fight one of the world's highest rates of rape, according to the author of a study in which 28 percent of men interviewed admitted they had raped someone.

Rachel Jewkes, of the South African Medical Research Council (MRC), said overhauling the criminal justice system would not be enough to reduce the number of rapes and that authorities must help do away with macho beliefs driving an AIDS epidemic.

"You are dealing with a problem which is sort of the behaviour of a quarter of the population. You can't address it through punitive measures alone," Jewkes, who heads MRC's Gender and Health Research Unit, said on Friday.

"Fundamentally, rape is a problem that stems from ideas of manhood in South Africa," said Jewkes.

"The position of men is superior to women in a patriarchal society and legitimates men's behaviours towards women, predicated on ideas of sexual entitlement and behaviours that demonstrate men being in control over women."

South African President Jacob Zuma has promised to end abuses against women. A polygamist who has angered women's rights groups, Zuma was acquitted in a rape trial in 2006, when he justified having unprotected sex with an HIV-positive woman by saying he had taken a shower afterwards.

The study, of men in all racial groups and from different socio-economic backgrounds, showed half of those interviewed were under 25 years of age and 70 percent were under 30.

Nearly 10 percent said they had raped a woman or girl for the first time when they were under 10 years old. The HIV prevalence among those who raped was 19.6 percent.

The MRC interviewed 1,738 men in rural and urban areas of the KwaZulu-Natal and Eastern Cape provinces.

RISKY SEXUAL ACTIVITY

There were officially 36,190 rapes in South Africa in 2007-2008 but many crimes go unreported.

Jewkes said the rape cases pointed to a range of risky sexual behaviour in South Africa, where about 12 percent of the population of 47 million people have HIV. About 1,000 people die every day from AIDS-related illnesses.

According to the study, men who said they had raped were more likely to have had more than 20 sexual partners, engaged in sex with a prostitute, raped a man and not used a condom consistently in the past year.

Jewkes said South African culture had left some with the impression that to be real men they need to have scores of partners, they should not be using condoms and can pay for sex.

Aside from ending what she called the machismo of some politicians, Jewkes said authorities must create jobs and educate young men to keep them from committing crimes like rape.

"Trying to change ideas of manhood in South Africa has got to be linked in a practical sense to being able to give men alternative models of how they can be men and how they can be successful and that means improving our education system ... and improving employment opportunities," she said.

But rape should not exclusively be linked to poverty.

"One of the really interesting findings from our research here is it's not the very poorest who are most likely to rape. It's actually men who are not very substantially advantaged but certainly more advantaged than the very poorest category."