The Broadcasting Standards Authority is investigating TVNZ's Breakfast presenter Paul Henry after he controversially called singer Susan Boyle a "retard" in November.
TVNZ upheld the complaints last month on the grounds Henry had breached the standard of good taste and decency.
Henry issued a written apology, but was not punished.
However, some complainants were not satisfied with TVNZ's actions and appealed to the BSA.
The complaints came after Henry was quoted from a magazine article that said Boyle suffered a mild intellectual impairment.
He then said: "Here's the really interesting revelation: she is in fact retarded...and if you look at her carefully, you can make it out."
BSA head Dominic Sheehan said some of the complainants had appealed on the grounds that Henry's comments were discriminatory.
"We'll be looking to see if [the apology] was sufficient in this case and if it wasn't, of course we might order something within our powers to occur. The discrimination complaint is a brand new thing and we'll be looking to see if [TVNZ] should have upheld that," he told the New Zealand Herald.
The Human Rights Commission also received more than 200 complaints but said it could not deal with them as they did not fall within the discrimination provisions of the Human Rights Act.
Other complainants to TVNZ have until early February to complain to the BSA if they are unhappy with TVNZ's action.
