NSW Police are investigating whether an internet forum on a ninemsn website called "Rape Club'' has been discussing rapes that have actually occurred or ones that are fantasy.

Ninemsn shut down the chatroom yesterday after it was told about a 15-month long discussion involving 46 web users or "posters'', discussing rapes and pictures of rapes.

It closed a further four rape-related forums connected to its website later today, ninemsn spokeswoman Kate Beddoe said.

The forums closed were "No Rape No Glory'', "Whitepower/rape rock'',
"Ministry's Land of Rape and Honey'' and "Rape me'', Ms Beddoe said.

"We are going through a process of reviewing any material that's brought to our attention and taking it down as appropriate,'' she said.

But whether or not the rapes were real or fantasy is now a matter for investigation.

NSW Rape Crisis Centre manager Karen Willis said she wanted rape fantasy internet discussions and websites outlawed as vilification of women.

Ms Willis said the chances all of the ninemsn posters were just fantasising about women was "pretty slim''.

"Someone who makes a career out of sexually assaulting women will often have started out fantasising and masturbating about it,'' she said.

"Then, as time goes on, their fantasies get more violent and they will get to the stage where they need to act out their fantasy.''

Professor of Criminology and Forensic Psychology at Bond University, Paul Wilson, said he was worried rape fantasy in Australia would link with actual rape.

Prof Wilson said in Japan, sex with violence in pornography, across all media, has been a common theme for many years, although the nation had very low rates of rape.

"There are a whole lot of cultural factors responsible for that,'' he said.

"Even though rape is not an uncommon fantasy among males, I'd be worried about western cultures which have high rates of rape, such as Australia, were rape fantasies a part of the media.

"I don't think that you can argue that just because they fantasise a lot about rape in Japan and have low rates of rape the same thing would happen in Australia.''