Work on a large area of land between Ribble and Dee Sts ceased late last month.
Yesterday, Heritage New Zealand Otago-Southland area manager Denise Anderson confirmed "a pre-1900 European/Pakeha domestic occupation site" was found by a consultant archaeologist.
While the exact nature of the remains was not yet known they were likely to be that of a cottage or similar structure, Heritage New Zealand archaeologist Matt Schmidt said.
"What's quite common around Oamaru, Dunedin and Invercargill is you'll find they've got lots of cottages around, so what you tend to find is the foundations of a cottage or house. That might be wooden piles, or maybe stone. Usually on the back you'll find rubbish pits and then latrines, and occasionally post-holes from outbuildings.
"It gives you an idea of the life of people living there. What they've been eating, what they've been buying, what they've been throwing out."
It could also be identified whether the structure was owned by a lower, lower-middle or upper-class family, which was often based on location, Mr Schmidt said.
An assessment is being carried out and a report on what was found will be compiled.
When completed, discussions will take place with developers before an authority is issued so construction can resume.
Mitre 10 Oamaru owner-operator Simon Lye said it was expected work at the site would resume "in a month or two".
"We recognise the importance of this process to the Oamaru community."
