In April, Invercargill city councillors Ria Bond and Ian Pottinger filed a code of conduct complaint against the mayor after his appearance on Guy Williams' satirical news show New Zealand Today.
The council has now confirmed a second complaint was made against Clark by an external party.
"I can confirm a complaint under the Invercargill City Council code of conduct has been lodged by the chief executive Michael Day. The complaint was made by an external party against mayor Nobby Clark," the council said.
"This is in addition and separate to the code of conduct complaint lodged against the mayor by councillors Pottinger and Bond.
"Both code of conduct complaints are currently following the process of determination and investigation of complaints. Upon completion of the independent investigation the reports will be dealt with in accordance with the process set out in the code of conduct."
Clark previously told RNZ the investigation into Bond and Pottinger's complaint was a distraction he did not need.
During his interview with Williams - described as "a train wreck" by one of his elected members - he defended previous instances where he has used the n-word and again repeated the slur.
Clark first courted controversy last year when he used the word at an Art Foundation event, supposedly to make a point around "tolerance" and "freedom of expression" within the art world.
He doubled-down on the matter during his appearance on the 21 March episode of New Zealand Today.
"If you had some rap music that come in, where every second word was n***, would that be okay? Certainly not to me," Clark said.
"Would you allow me to stop that."
Clark claimed to hate the term but again used the slur when citing the name of an Invercargill street gang.
"It's offensive to people."
He also asked Williams if he was gay.
"You (Williams) tend to be leaning towards minority groups," Clark proposed.
"I'm not leaning towards," Williams replied.
"Well all right bent over towards them," Clark quipped.
Bond and Pottinger said the "mayor's conduct in this interview was reprehensible".
"It is our belief that mayor Clark, through his language and actions has breached council's Code of Conduct on three counts," their complaint said.
"The conduct caused serious harm, for example, reputation harm or brought Council into disrepute.
"During the interview the mayor repeatedly used the 'n' word and showed no remorse for his actions. During the interview, on one occasion, mayor Clark also flaunted a copy of the book Twisting the Treaty towards the camera. The reason we mention this is that to associate a book related to the Treaty of Waitangi within an interview concerning the use of the 'n' word, we believe, is sickening."
The council's statement on the latest complaint did not include any comment from Clark.
A council spokesperson confirmed Clark would not make any comment on the matter until the investigation was complete.
The council, late last month, asked for all media requests for the mayor to be directed to the council's communications team.
"The mayor receives a large number of media queries, and this is important to ensure he can provide a timely and helpful response, and to ensure his availability when arranging phone or in-person interviews."
RNZ
