Central Otago sub-area supervisor Senior Sergeant Ian Kerrisk and his wife Meredith bought the historic building and accommodation complex on Friday.
After 37 years in the police, it was "time for a change", Snr Sgt Kerrisk said.
"Meredith has supported me with my policing career ... she has a background in hospitality and is from Clyde ... it’s time for me to support her career."
Snr Sgt Kerrisk said he would leave the police at the end of January.
The Kerrisks bought the House from John and Maree Davidson, who had owned the building and the Bank Cafe beside it since 2005.
He said he was excited by the opportunity of trying something different.
"Dunstan House is unique and it’s been completely updated by John and Maree."
The Davidsons earthquake-strengthened and refurbished part of the house’s interior.
Mrs Kerrisk said they had plans for the building but those were "under wraps".
The Kerrisks would not disclose the purchase amount but QV.co.nz said the House’s rating valuation was $1.05million.
The Kerrisks said they had not purchased the Bank Cafe, which was adjacent to Dunstan House, still owned by the Davidsons but on the market.
Mrs Davidson said she and her husband would hand over the house to the Kerrisks by February 20.
She admitted the news was "pretty fresh for us" and had not spoken to the Kerrisks so did not want to comment further.
Before the Davidsons, Will and Caroline Kealey owned the house for nearly five years.
Fleur Sullivan owned the house between 1997 and 2000.
