An acclaimed 300-piece New Zealand art collection, including works by the likes of Colin McCahon, Don Binney and Ralph Hotere, has fetched a whopping $3 million at auction.

After 50 years in the making, the treasured modern-art collection of Warwick Brown and his late wife Kitty went under the hammer at Mossgreen-Webb's in Auckland on Wednesday and Thursday.

Self-confessed art collector Warwick Brown sold the collection to free up space and capital to enable the resumption of his life-long collecting habit.

Nearly 100 works sold on the first night, including Binney's iconic La Chute d'Icare, Pureora: Last Flight of the Kokako. The 1979 oil painting of a kokako in flight sold for $529,000 making it the most expensive work ever sold by the artist.

Binney's Flight of the Kokako sold for a record price of more than $500,000. Photo/Supplied
Binney's Flight of the Kokako sold for a record price of more than $500,000. Photo/Supplied

Spirited bidding saw This is a Black Union Jack by Hotere, fetch $169,000 on Wednesday. About 180 per cent more than the lower estimate of $60,000.

Two significant works by McCahon also sold at auction, for over $300,000. His Rocks in the Sky, Series 2, No. 4: Seagulls. Rain, one of the gems of the collection and a seminal work by the artist, achieved $369,000.

The second half of the collection, presented on Thursday night, was met with even greater voracity of appetite by the buying audience.

With artworks estimated at more accessible price points, the selection, including works by McCahon, Gordon Walters, Michael Smither, Jenny Dolezel and Jeffrey Harris, attracted the attention of collectors nationwide.

Brown was delighted with the results of the sale and in particular the response to the smaller works sold on the second evening.

"It was rather amazing to see the works from the early days of my collection fetch such high prices, but even more satisfying for me was to see the works I acquired later on, by emerging artists, go so well on the second night of the sale," he said.

"They are like old friends to me, and it was wonderful to see them receive such a warm reception."

The couple started collecting in the mid-1960s, when contemporary art in New Zealand was in its infancy, and from which a new generation of artists and intellectuals rapidly emerged.

Believe it or not, Brown did not buy work with financial gain in mind.

Instead, they collected works by their friends and contemporaries, selecting works that resonated with them personally, eventually amassing a collection that spanned the breadth of modern and contemporary art practice.

Mossgreen-Webb's director of art Sophie Coupland said it was a privilege touring and selling the unique collection and "an absolute pleasure having the collector, Warwick Brown, so actively participant in the process".

"We couldn't be happier with the results."