The Government more than doubled its intended contribution to the Awaroa Beach bid at the last minute when it looked set to fail, official documents show.
The pristine Abel Tasman beach was purchased for around $2.8 million in February, largely thanks to a fundraising campaign on Givealittle.
More than $2 million was raised via the website, $250,000 was donated by the Joyce Fisher Charitable Trust and the Government also chipped in $350,000 to help secure it.
The Government's contribution came from the Nature Heritage Fund (NHF) which is a contestable Ministerial fund administered by an independent committee and serviced by the Department of Conservation.
Documents released to Newshub under the Official Information Act show, the NHF only recommended spending "up to $150,000 excluding GST" on the campaign.
In a letter to the Associate Conservation Minister Nicky Wagner, the NHF said its money should only be used as a "last resort" and wanted it to be confidential should the money not be needed.
That money was approved on February 18 -- days before the campaign deadline.
But in a document dated March 3 between the Department of Conservation and Ms Wagner, the contribution was bumped up to $350,000 -- just under half of the fund's remaining budget for the 2015/16 year.
In a statement, Ms Wagner said the increase in contribution was a decision made by ministers during the final stage of the campaign when it "became apparent the bid was not going to succeed".
But Ms Wagner concurred with Conservation Minister Maggie Barry, who called the Government contribution "modest" and "good value" for taxpayers, especially considering the $1.9 million the fund wanted to spend a decade ago.
"While the Givealittle campaign was an unusual way for the purchase to succeed -- indeed, an unprecedented one -- the final result is that the Abel Tasman National Park receives a piece of land for far less cost to the taxpayer than if the 2006 tender had succeeded."
It was the second time the Government, through the NHF, tried to buy the same piece of land.
In 2006, the NHF recommended bidding $1.9 million on the 7.36 hectare sandspit at Awaroa with the intention to add it to the existing Abel Tasman National Park which it sits inside. However, the offer was ultimately unsuccessful.
Dr Gerry McSweeney, a member of NHF since it was formed in 1990, says the land was extremely overvalued for what it was, calling the asking price "almost extortion".
He suggested the Government wanted to cash in on the feel-good factor of the crowdfunding campaign by chipping in on the bid.
"For Christ's sake, it was a mortgagee sale. BNZ desperately wanted to get money.
"I would have expected less than $1 million at the most. The nation ended up paying three times that," he says.
While the NHF thought the land had strong recreational value, he thought it would be "most unlikely" it would have forked out the full, or even half, the asking price if buying it outright.
When asked whether the Government and Ms Barry wanted to bask in the reflected glory of the campaign, Dr Sweeney laughed: "I couldn't possibly comment; yeah, of course they were".
"Think of the minister, she wanted to be part of this whole thing too."
Dr Sweeney believed in the greater cause of the fund, despite some "little hiccups" in its history.
"There's been many occasions over 25 years where one might tender one's resignation but you tend to sometimes bite your tongue and say 'well we'll endure longer than these guys and what we're working for is collectively really good even though individually there's some little hiccups along the way'."
DOC has previously said the land was of low conservation value -- something Dr Sweeney "wouldn't disagree with".
The NHF's aim is to protect indigenous ecosystems which "represent the full range of natural diversity originally present in the New Zealand landscape by providing incentives for voluntary conservation".
Since 1990, it has protected more than 340,449 hectares of indigenous ecosystem through legal and physical means including direct purchasing, covenanting or fencing.
At the time the Government was discussing how much to put in for the beach, the NHF had $725,764.25 in its 2015/16 budget left.
It has a budget of $1,803,000 for each of the next two financial years.
Labour leader Andrew Little believes the Government's contribution was a good use of money.
"It was a symbol about saying 'this is who we are as New Zealand. We want to hold onto this rather than see it go into other hands'."
The land purchased includes more than 800m of beach, native bush, three buildings and an airstrip and will eventually be included in the Abel Tasman National Park.
The campaign to buy the beach captured the imagination of many Kiwis, with just shy of 40,000 people donating to the cause.