Heritage New Zealand senior archaeologist Frank van der Heijden said the necessary authority was granted to the company as the tavern was built before 1900 and therefore an official archaeological site.
An LEP Group spokesman said Opus archaeologists had been working on site to document the area of significance, and understood the remains were still on site.
"The site had already been blessed before the remains found and we notified local iwi and Heritage New Zealand and that's obviously sensitive with the remains in place."
He said he didn't want to go into more detail but there was a process in place with both entities to ensure the remains were disposed of correctly.
Mr van der Heijden said a condition of the authority granted by Heritage New Zealand was that the moment suspected remains were found works had to immediately stop and police, tangata whenua and Heritage New Zealand notified.
Protocol had been well followed in this instance and the process to consult with iwi was now under way to determine how to proceed, he said.
The archaeologist said finding remains was often expected in certain landscapes where subdivisions were being built. However, he said this location was more unusual.
"We always provide for the possibility that remains are found. In an archaeological context I would say this happens regularly [but] in this case it was slightly more unexpected than others."
Being the site of a historic tavern, Mr van der Heijden said it was common to find rubbish pits which contents often gave insight into how those in the past lived.
The level of research, analysis and report writing about the remains would be determined by local iwi; specifically how comfortable they were about the situation.
Anyone who found skeletal remains was encouraged to contact local police or Heritage New Zealand to ensure the remains were "treated sensitively and with respect", he said.