Police Commissioner Peter Marshall has faced tough questions by MPs over an investigation into a teenage sex ring uncovered in Auckland.
Mr Marshall told Parliament's Law and Order select committee on Wednesday that police communication about the case should have been sharper.
Police came under scrutiny in November this year for their investigation into a group of young men who had boasted online about having sex with drunk and underage girls.
Police claimed they were powerless to act without formal complaints, but it soon emerged that four girls had previously come forward.
Mr Marshall told MPs on Wednesday that their communication around that should have been sharper.
However, when asked whether public confidence in police had dipped as a result, he said we would never know.