Four gutted, decapitated eels left in a neighbour’s letterbox were among a campaign of harassment that drove a man from his home.

What began as a neighbourly dispute in Marlborough over missing mail spiralled into a sustained pattern of degrading and threatening acts by Graeme Dynes.

It included racist language, dog faeces thrown across the neighbour’s lawn, sexual gestures and dead eels and mussels left in his mailbox.

Dynes, 67, was convicted of criminal harassment after a judge-alone trial at the Blenheim District Court.

He later appealed his conviction and sentence, but the High Court has dismissed the challenge, finding it was open to the trial judge to conclude Dynes intended to cause fear.

The senior court’s recent decision detailed how the harassment escalated over more than a year.

The neighbour became concerned for his safety and installed cameras, which captured Dynes making sexual gestures in front of them and throwing a greasy, fatty substance at his car.

For six months, the neighbour said Dynes left dead fish in his letterbox alongside notes accusing him of being a sex offender.

On one occasion, four dead eels, gutted and decapitated, were left in the man’s letterbox.

The victim gave evidence at the judge-alone trial that the escalation in behaviour made him feel vulnerable and unsafe in his own home. He eventually moved out.

Dynes argued any acts the court found he engaged in were not intended to make the victim feel unsafe.

But Judge Joanne Rielly found Dynes’ evidence inconsistent, noting that he accepted engaging in the behaviour only when it was captured on camera.

Judge Rielly concluded police had proved the charge, imposing 18 months’ intensive supervision and four months’ community detention, as well as $1000 in reparation.

Dynes went on to appeal his sentence and conviction, arguing the judge applied the wrong legal standard by finding he was “likely” the person who threw the objectionable items into the victim’s yard, and failed to explain why she found him an “unconvincing witness”.

He also maintained it was not his intent to make the victim feel scared.

In the High Court decision, Justice Robert Osborne agreed “likely” was not the correct standard but found the error immaterial.

“The court finds that there is support for it being the defendant who placed mussels and eels in the complainant’s letterbox because he reported that he did so on at least one occasion to others,” the decision said.

“The only logical inference to be drawn is that the person who put fish items in the letterbox on one occasion did so on all of the occasions reported by the complainant given the frequency and timing of that occurring.

“I am satisfied the judge was correct in relying on such an inference that it was Mr Dynes who put the fish in the victim’s letterbox.”

Justice Osborne also found Judge Rielly gave a well-reasoned analysis of why she rejected Dynes’ evidence.

“Many of Mr Dynes’ acts had an inherently threatening nature about them. For example, the leaving of a decapitated eel in the victim’s letterbox. Similarly, the aggressive notes. Similarly, the ‘nasty racist language’. Similarly, the rude gestures,” Justice Osborne said.

“In other words, harassing someone with the aim of driving them from their home, where the acts involve an undertone of violence, amounts to an attack on the victim’s mental wellbeing. I am satisfied it was open to the judge to infer Mr Dynes intended to cause fear to the victim.”

At sentencing, police sought reparation for car cleaning, paint and panel repairs, and installation of CCTV.

Justice Osborne accepted Dynes’ lawyer had been “taken by surprise” by the request, noting the sentencing had to be stood down so counsel could take instructions “on the hoof”.

The High Court upheld the conviction and sentence of community detention and intensive supervision for criminal harassment, but directed that the reparation issue be revisited by the District Court.