In the piece, the endangered kokako is shown in its tumbling flight, its slate-grey plumage, bright wattle and black eye-mask all clearly visible.
According to Brown, a well-known art writer, critic and curator, the painting was done as a fundraising exercise for environmental group, The Native Forest Action Group.
The reference in the title to Pureora refers to the successful campaign by environmentalists to protect the ancient forest from logging.
The threat to the kokako is signified by the log skidder and a forestry worker.
The large size of the bird is thought to signify the success of environmental activism in this case.
Brown decided to sell the entire collection after his beloved wife Kitty passed away in August last year.
"I just woke up one morning and thought I'm going to sell the collection and I'm going to memorialise my marriage and I'm going to clear the decks so that I have some empty space on the walls back home," he said.
"And maybe I'll start all over again and look to the future."
La Chute d'Icare, Pureora: Last Flight of the Kokako is one of 300 pieces of New Zealand art in the Warwick and Kitty Brown Collection which will be sold in its entirety, over Wednesday and Thursday.
The collection of contemporary art over the past 50 years also features works by Colin McCahon, Tony Fomison, Pat Hanly and Ian Scott.
The entire collection could fetch upward of $1 million.