The Newmont Gold Company - which manages in the Martha Mine in the Waihi township - says the Hauraki District Council will take the lead in determining the cause of subsidence beneath houses in Waihi.
In the last six weeks, ground movement has affected six properties in Gladstone Road and caused cracking on Walmsley Road, at the foot of the Coromandel ranges.
Newmont has offered to buy the affected houses as a goodwill gesture, and will also pay for relocation costs, but says the subsidence has not been caused by recent or historic mining activity.
A company spokesperson, Kit Wilson, says the cause remains a mystery, and an investigation into the subsidence is in the hands of the council.
On Monday, Hauraki District Council said the subsidene was not caused by a sinkhole and the ground movement appeared to be very localised at that stage.
The affected area has been residential since the 1980s.