Jeremy Buis was found guilty of criminal harassment, threatening to do grievous bodily harm and intentional damage after a judge-alone trial in March.
Buis waged a two-and-a-half-year harassment campaign against Dunedin businessman Danny Pryde after a parking complaint led to the police officer being ticketed.
The officer was suspended from his role in February 2015 and remained on paid leave until earlier this month.
However, Southern district police confirmed on Wednesday Buis had ''tendered his resignation earlier this month''.
''It was accepted,'' Southern district commander Superintendent Paul Basham said.
''This resignation came prior to an agreed meeting with myself, scheduled for this Friday, regarding the outcome of the employment investigation.
''As Buis no longer works for police, I am now in a position to be able to comment on his conduct, which has been a matter of public interest for some time now.
''The actions of Buis were disgraceful. This behaviour does not reflect on the actions of other staff in the Southern policing district.''
Buis sought to suppress his occupation following his sentencing in April. However, that was rejected after the Otago Daily Times appealed the decision to the High Court.
Mr Pryde, who owns an engineering firm, never met Buis until June 14, 2012, when he parked his vehicle blocking an entrance to Pryde Engineering.
Buis' car was ticketed at Mr Pryde's request and what followed was an orchestrated campaign of harassment which included anonymous text messages, the victim's contact details being plastered up at a Dunedin gay hangout and the creation of a fake homosexual dating account using photos from Mr Pryde's work website.
Mr Pryde said it had been ''a living hell'' and he believed he was going to be killed during the ongoing harassment.
Supt Basham said Southern police wanted the trust and confidence of the public.
The majority of staff worked ''hard every day to provide a quality service to members of the public''.
''We understand the actions of one officer can impact on the reputation of the whole organisation,'' he said.
''For that reason, these types of matters are always investigated impartially to the highest standard, with a view to holding staff accountable if they have committed a criminal offence or not acted in accordance with our values.
''I want to take this opportunity to reassure the public that this kind of behaviour will never be condoned by me, or by the other good men and women who collectively make up the Southern policing district.''
