Wanganui Police Constable Hayden Bradley, who was recently acquitted of corruption, has resigned.
Central District Commander Superintendent Russell Gibson said: "It is clear to me that Mr Bradley accepts his behaviour was inappropriate and goes against police values and ethical standards.''
An employment investigation which began following Mr Bradley's acquittal would not be completed as a result of his resignation, Mr Gibson said.
"I want to take this opportunity to reaffirm my praise to the woman who spoke up and told the Wanganui police about Mr Bradley's conduct.
"This woman has gone through some very difficult and emotionally testing times but through this whole process she has acted with integrity and strength.''
Mr Gibson also praised the "professionalism of the Wanganui officers that dealt with the woman's complaint''.
"I want to reassure the public that the actions of this officer are not a reflection of the New Zealand Police.''
Mr Bradley was acquitted in the High Court at New Plymouth earlier this month on one count of corruption and bribery of a law enforcement officer.
The jury took less than three hours to return a unanimous verdict.
Mr Bradley had been accused of seeking sexual favours in return for not prosecuting a 27-year-old woman who he pulled over for driving while disqualified on February 5 last year.
Defence lawyer Susan Hughes QC told the court the only thing Mr Bradley had sought was an assurance the woman would not talk about his decision not to charge her.
The trial heard evidence that officers must charge people caught driving while disqualified because the offence could lead to imprisonment.
Ms Hughes said the sexual innuendo, flirting and "silliness'' recorded in a conversation between Mr Bradley and the complainant as he drove her home from a bar in central Wanganui on February 7 last year was never linked to the prosecution of the woman's disqualified driving.
"He has shamed himself, embarrassed his family and humiliated his wife. He should hang his head, he should be ashamed, but a criminal he is not,'' Ms Hughes had said.
Mr Bradley had been suspended on full pay since the allegation emerged until the end of the trial.
At the end of the trial, New Zealand Police Association spokesman Emmet Lynch said Mr Bradley was considered a hardworking and reliable policeman.