An Australian internet chat group where members boast of raping women has been removed after operating for more than a year on one of the country's most visited websites.

The discussion group dubbed "Rape Club" was set up on the NineMSN website in February last year and, as of last night, had 67 members.

The site, which had been freely available for the public to access, featured various posts relating to the raping of women.

One post, sent by an anonymous user on May 14, offered pictures of a raped woman.

The site appeared among a list of miscellaneous chat groups on the same web page as a site for the St Johns Ambulance Service and the charitable Make-A-Wish Foundation.

Adding further insult to sexual assault victims, the site's offensive content was accompanied by an official NineMSN welcome post that automatically greeted each new member.

"Welcome to Rape Club. Whether you are a manager, member or visitor here, we hope you enjoy this NineMSN group," the message stated.

Shocked NineMSN managers removed the site from their web pages last night after being contacted by The Daily Telegraph newspaper.

"You may be able to tell by my silence right now that it is obviously not one that we are aware of," NineMSN corporate communications manager Kate Beddoe said.

NineMSN does not employ staff to monitor the content of its chat sites, instead relying on the public to alert it to offensive material.

Rape victims' support groups have expressed outrage that the chat site was allowed to operate for more than a year.

"It makes my stomach turn just thinking of it," New South Wales Rape Crisis Centre manager Karen Willis said.

"Just think of the level of violation and fear and shame and anger it would invoke in any sexual assault victim who happened to come across it."

Police have launched an investigation into how the site was formed.