A South African inventor is attempting to curtail rapes in a country with one of the highest rates of sexual assaults in the world with a new condom.

He unveiled a new "anti-rape" female condom on Wednesday that hooks onto an attacker's penis.

"Nothing has ever been done to help a woman so that she does not get raped and I thought it was high time," Sonette Ehlers, 57, says of the "rapex," a device worn like a tampon that has sparked controversy in a country used to daily reports of violent crime, according to Reuters.

Police statistics show more than 50,000 rapes are reported every year, while experts say the real figure could be four times that as they say most rapes of acquaintances or children are never reported.

Ehlers say the "rapex" hooks onto the rapist's skin, allowing the victim time to escape and helping to identify perpetrators.

But the "rapex" has raised fears amongst anti-rape activists that it could escalate violence against women.

"If a victim is wearing such a device it may enrage the attacker further and possibly result in more harm being caused," says Sam Waterhouse, advocacy coordinator for Rape Crisis.

Other critics say the condom is medieval and barbaric -- an accusation Ehlers says should be directed rather at the act of rape.

"This is not about vengeance ... but the deed, that is what I hate," she says.