"Children look up to athletes and while roller derby may walk a fine line between appropriate behavourism with suggestive names and uniforms, no one can argue that the word has any place in sport or in public."
Another spectator, who asked not to be named, said she was "absolutely disgusted and outraged".
She said she couldn't believe the words were acceptable at a "family-friendly event" with "multiple sponsors paying to be associated with this league".
"The attitude encourages a negative mentality within the community. It's not okay to be using these words, even in jest."
Otautahi Roller Derby League marketing and public relations spokeswoman Michelle McConnell said the offending pants were being "retired".
"The skater has apologised to the league for the controversy caused and regrets any disfavour spread to our associated groups".
She said the league was "against discrimination and victimisation of any group, unanimously and actively".
The slogan had been "misinterpreted and used as leverage in an attempt to defame our league".
Ms McConnell said the player's skating name, number and pants slogan were references to her favourite band Wu-Tang Clan - an American east coast hip-hop band.
The intention was to "associate her alter-ego as being part of the community who use that phrase - an in-joke for fellow Wu-Tang fans".
The player did not return calls but said in a post on her Facebook page: "having a team of haters on me is kinda weird, but what is awesome about it is all the messages of support in my inbox this morning."
Human Rights Commission spokeswoman Vicki Hall said: "While the slogan may give offence to some, it is not clear that it breaches the Human Rights Act."
