Simon Sutherland and Jennifer Jones, of 44 Seaview Tce, St Clair, said they have been living a "nightmare" since Dunedin man Bourke Thomas purchased two vacant sections next door in early 2004.
Since then, the couple had been forced to watch from their bush-clad home as Mr Thomas came and went, trees were cut down and a steady stream of building materials and machinery - not to mention vehicle wrecks and even a kitchen sink - piled up next door.
The material soon began to spill over on to a shared right-of-way driveway, providing access to the couple's home and Mr Thomas' sections, and some of it even made its way on to couple's own property, Mr Sutherland said.
The Otago Daily Times visited the properties this week and found piles of material still on site, as well as two structures the couple said were a storage shed and workers' hut used as accommodation.
Neither of the buildings had resource or building consents, Mr Sutherland said. The couple had pleaded with the council to enforce district-plan rules, which they believed prohibited the type of activity taking place next door.
Council staff had taken some action, with repeated site visits, warnings and an abatement notice issued against Mr Thomas, but that had failed to resolve the issue, Mr Sutherland said.
South Dunedin police have also been called to the property on at least six occasions, following alleged threats, standoffs and the theft of items, but there was insufficient evidence for a prosecution, Senior Sergeant Phil McDouall said.
Mr Thomas would not talk to the ODT when contacted this week, hanging up - twice - when asked about the couple's claims.
However, Mr Sutherland said the problems became so bad the couple paid $6000 to have a private driveway built on their section, just to avoid Mr Thomas.
Mr Sutherland had also sought legal advice because of the council's unwillingness to take stronger action, but was told a civil action could cost $40,000.
Instead, he was now pinning his hopes on the Office of the Ombudsmen, hoping it would force the council to take stronger action.
The couple had prepared a written account of each altercation with the neighbour, detailing every angry exchange and disruption over six years.
That included the noise from a compressor and a jack-hammer being used on the sections, sometimes until 9.30pm, followed by the operation of a mud-brick machine, Mr Sutherland said.
"It resonated around the whole valley, and the smoke - it was like going back to the Industrial Revolution in London," he said.
Action by council staff had resulted in the mud-brick machine eventually being shut down, and car wrecks removed, but other problems persisted, he said.
He had received letters from Mayor Peter Chin and council chief executive Jim Harland sympathising but advising little more could be done.
"There are some residents in our community whose living habits and what they do to their property falls short of what most people would expect," Mr Harland's letter said.
Another letter, from council senior planner Doug Spittle in September last year, said activity on the sites was permitted, as it was in keeping with a planned residential development.
Mr Sutherland said Mr Thomas had initially talked about building a family home on the site, but nothing like that had happened.
The only building activity in six years had been construction of the storage shed and workers' hut, both of which lacked consents and were illegal, he said.
Mr Sutherland's wife was equally distraught and frustrated by the council's failure to act.
"It's in the too-hard basket for them [the council], but what are we supposed to do? Surely six years is long enough to ask for some action to be taken," Ms Jones said.
Mr Sutherland said tenants renting other neighbouring homes had quickly come and gone over the years, and the couple had considered selling their home, even if it meant taking a financial hit from reduced property values.
"You can't possibly know how it is living through it. It is just incredible. It's just worse than you can ever describe.
"I wouldn't wish it on anyone - it's a nightmare."
Council staff across several departments have dealt with complaints levelled against Mr Thomas, but inquiries by the ODT were directed to council resource consent manager Alan Worthington.
Mr Worthington acknowledged a complaint by the couple was being investigated, and said staff would co-operate with the Ombudsmen.
He would not comment on the detail of the case, saying he wanted to protect the integrity of the process and the privacy of all parties involved.
However, there were "always two sides to the story", he said.
"It's one we have been investigating and it's an ongoing investigation.
"Some people might be unsatisfied with a situation - some things are easily resolved, and some aren't."
Snr Sgt McDouall said police dealt with many "neighbours from hell", with disputes often triggered by shared right-of-ways, and every complaint was investigated.
"It's unfortunate, but it goes on all over the place. Neighbours can't get on with each other."
However, investigations into claims of theft - and other allegations - at Seaview Tce had been met with denials and there was a lack of evidence, he said.
"There's always one [neighbour] worse than the other, but they are not helping each other. They get to a stage where they are so set in their ways, neither of them wants to back down.
"We don't have a crystal ball, unfortunately."
In early 2008, Mr Thomas told the DScene newspaper he had "no problems" with any of his neighbours.
"I will say it again and I'll say it quite clearly: I have no problems with my neighbours."
