A derelict house was dumped on a vacant south Auckland site, setting back development for a new retail centre.
The graffiti-covered dwelling appeared overnight on a lot on Manuia Rd, Takanini on November 18 or 19.
Rod Bray, Northbridge Properties project development manager, suspects the culprit was looking to cut costs.
"The house is derelict. It's not really worth anything; it has no salvage value," he told Newshub.
"When a house is in that kind of condition, the only thing to do is to demolish it."
Demolition comes at "significant expense", Mr Bray says, so the culprit seems to have chosen another way.
"The options are either pay to have it demolished, or you dump it somewhere else and make it someone else's problem."
The appearance of the house on the recently cleared site has "thrown a spanner in the works" of a new retail centre's construction timeline. It will cost between $20,000 and $30,000 to remove the house, a process which will likely delay development originally planned to start in 2018.
Mr Bray says in the last day or so he has received new information giving the investigation a lead on the culprit's identity. He is offering whoever dumped the house an opportunity to come forward and claim responsibility before criminal charges are pressed.
"We'd like to get going fairly quickly, so we'd love to have this issue resolved and we'd appreciate any help."
A $1000 reward is being offered to anyone who provides information that will crack the case.