Wanganui Mayor Michael Laws says a meeting between councillors and representatives from the Hells Angels Motorcycle Club on Friday was very disappointing.
Five Hells Angels members were to appear before a council sub-committee to discuss a bylaw banning gang patches in the city.
But, only one, Wanganui chapter president Wayne Tweeddale attended, with his lawyer.
During the meeting, Mr Tweeddale refused to answer questions, saying he was angry the time of the meeting had been changed at the last minute.
Mr Laws says Hells Angels did not explain why they should not be considered a criminal gang.
The bylaw will come into force on 1 September.