The country's race relations commissioner is blasting a real housewife for uttering a racially charged slur against a co-star on a hit reality television show.

Dame Susan Devoy says in the upcoming Real Housewives of Auckland episode a derogatory term is used by Julia Sloane which she says demonstrates the ugly face of casual racism.

In previews to tomorrow night's episode viewers are told to brace themselves for one of the most shocking moments this season.

The Herald on Sunday revealed yesterday Sloane called fellow housewife Michelle Blanchard a "boat n*****" during filming off the coast of Australia.

An apology has been made but yesterday Sloane's husband Michael Lorimer said it was a term he and his wife used tongue-in-cheek when sailing. It wasn't intended to be racist, he said.

Devoy said while while it showed some New Zealanders still thought it was fine to say ignorant, offensive and racist things it was up to the rest of the community to tell them it was not okay.

"I do not think that ignorant, overt racist behaviour is part of Kiwi culture so we all need to call it out when it rears its very ugly head. People like Julia need to understand that using words like that is not how we roll here. That is not us."

Dame Susan said while she had not seen the episode she was interested in what reaction was shown by the rest of those on set.

"I haven't seen this episode yet but am interested to see what the rest of the housewives and film crew did when Julia referred to Michelle using a hateful racist word. Does anyone challenge her? Does anyone tell her to pull her head in?" asked Dame Susan.

"I'm sorry for Michelle but this episode will educate a lot of people about so-called casual racism. The thing about casual racism is it never feels casual when it's happening to you or your loved ones."

Dame Susan said people like Julia do not reflect the vast majority of New Zealanders and challenge all racial intolerance whenever we were confronted by it.

She said it was important for New Zealanders to talk about what was acceptable and what wasn't as we lived in one of the world's most ethnically diverse, as well as one of the most peaceful nations on earth.

NZ Herald