Thirty firefighters from three brigades fought in vain to save the large house in Glencoe Rd, Crown Terrace.
Police were unable to provide any details about the dead man, who collapsed and died at the scene, but it is understood he may have been a neighbour and was not in the house at the time of the fire.
"Details are very sketchy at this time," Senior Constable Julian Cahill said.
The house is believed by the Otago Daily Times to be owned by Coutts, who is understood to be overseas.
Coutts' name is not on Queenstown Lakes District Council's 2008 rates database as the owner of the 41ha property, which lists its capital value as $4.5 million, but was named as its owner in a 2007 resource consent application.
It is understood Coutts' family was shocked by last night's events and did not wish to comment.
A St John spokeswoman confirmed a 48-year-old man had died at the scene.
His wife called fire and ambulance after he collapsed outside the house, she said.
CPR was carried out by firefighters and then ambulance staff.
The man's wife was uninjured.
Arrowtown fire chief Garry Hall said appliances from the Arrowtown, Frankton and Queenstown brigades, and two ambulances, raced to the scene after the alarm was raised about 7pm.
But by the time they reached the house it was already totally involved.
First on the scene was a 4WD unit which took a short-cut via Tobin's Track, a back road from Arrowtown across the Arrow River.
Glencoe Rd is about 25km from Queenstown, about 1.5km above the zig-zag section of the Crown Range Rd.
The glow from the fire could be clearly seen from just past the Frankton turnoff.
Mr Hall said four crews wearing breathing apparatus had been part of the firefighting contingent.
Water to fight the blaze had to be pumped from a large pond about 150m from the house.
There had been problems initially getting the supply flowing because of the low level in the pond and two pumps had to be used.
It is understood construction work was under way at the large house.
Last night, there were two or three Rilean Construction vehicles parked in the long driveway which leads to the home from Glencoe Rd.
Rilean director Gary Dent last night declined to comment when contacted.
Police and fire were still on the scene late last night and a fire safety investigator will travel to the site this morning.
