An expert in art crime believes the ram-raid robbers who stole two valuable Lindauer paintings could try and offer them for ransom.
Estimated to be worth around $1million as a pair, the brazen art heist - unprecedented in New Zealand's history - took place in the early hours of Saturday when a vehicle crashed through the glass front of the International Art Centre in Parnell.
Thieves snatched the two masterpieces, which were on display in the gallery's street-side front window.
Masterfully crafted by celebrated artist Gottfried Lindauer in 1884, the highly-valuable works are known as known as "Chieftainess Ngatai - Raure" and "Chief Ngatai - Raure".
They were set to be auctioned at gallery on Tuesday night as part of an "important and rare" exhibition.
Art historian Dr Ngarino Ellis, who runs a class on art crime at the University of Auckland, said the theft ranked as one of New Zealand's biggest ever art crimes.
"It's quite incredible that someone's actually done this," Ellis said. "Lindauer and Goldie, to steal one of those is very unusual - you just simply wouldn't be able to sell them in New Zealand.
"They probably thought they could steal them, try to sell them on the black market, or ransom them, which they might try to do. That wouldn't surprise me.
"People have tried to do that before in New Zealand but not with Goldie or Lindauer, but it is known overseas that some art thieves try and get ransoms."
Ellis said there wasn't much of a black market for art in New Zealand, and they were more prevalent in countries where large organised crime syndicates operated.
"The ransom thing is usually politically-motivated with groups who have some agenda. Or else it's just a common thief who wants to try and get some money."
She said displaying the Lindauers in the front window was "tempting fate".
"Given the prices that the International Art Centre can get for paintings like that - I'm not sure extra security was taken, I presume it was - I'm not sure that that was the most prudent thing to do."
Police hunting the masterminds behind the brazen art theft yesterday confirmed they had alerted Interpol and Auckland International Airport to the stolen objects.
Inspector Matt Srhoj wouldn't comment on what actions police would take should a ransom be made, nor on whether police would consult the descendants of Lindauer's subjects.
"It's always a possibility [that the paintings will be taken overseas]. But I couldn't really speculate as to the motives or reasoning behind the burglary at this stage or where these paintings might end up," he said.
"Obviously we're hoping to recover the paintings - they're a significant piece of New Zealand's art history."
He said the vehicle that was used in the robbery - which an eye-witness told the Herald on Sunday was a Ford Courier ute - had been stolen nearby and then driven up Parnell Rd to the gallery, before turning and reversing into the shop front.
"It was a quick offence, a smash and grab situation," Srhoj said.
"These things happen very, very quickly so it's difficult to establish early on how sophisticated it was. But it's obviously going to take a certain amount of planning."
As the search continued for the rare and expensive artworks, two men who were the first on the scene after the ram-raid said it appeared the operation had taken just a matter of minutes.
Scott Belcher, the manager of Pineapple Bar which is across the street from the gallery, was closing up with two other staff members about 3.45am when he found out about the robbery.
One of the staff members, who wanted to remain anonymous, told the Herald on Sunday he realised the gallery's window was smashed when he went to clear the ashtrays in the bar's outdoor area.
He hadn't heard the glass smash because the music was still on inside the bar. The last customers had left Pineapple Bar just 15 minutes before the ram raid.
The Ford Courier ute which had been used in the attack was still partly inside the gallery and its engine was still running but no one was inside the vehicle, he said.
"I just saw the car completely totalled and I was like 'this is strange'."
He ran inside and told Belcher who called the police at 3.50am.
Both men said they didn't hear any alarms going off and Belcher said the police, who were on the scene in just two minutes, told him they hadn't known about the break in until they got his call.
He said the police told him the vehicle used in the robbery had been stolen.
"[The robbers] used a local ute that had been hot wired as a battering ram. It all happened within about five or six minutes."
The alleged offenders, believed to be two men, fled in a white Holden with blue flashing lights obscuring the number plate, Belcher said.
Victoria University Associate Professor of Art History Roger Blackley said it was highly likely the paintings sustained damage in the raid.
"A very delicate film of canvas is not something that should have glass shattering on top of it," he said.
The works were painted in Lindauer's most productive period during the mid-1880s, a time when the artist created his greatest works.
"They're quite important to the history of New Zealand ... and also this is internationally significant."
Blackley said the theft was "quite idiotic" because you wouldn't be able to display them in public.
"And even if you thought you were liberating these works from the clutches of the Pakeha marketplace, if you're motivated by affection for the paintings you've probably irreparably damaged them."
Artist and Maori sovereignty movement figurehead Tame Iti only heard about the theft when contacted by the
Herald on Sunday
and wouldn't speculate on the criminals' motives.
However, he said there needed to be more debate around who owns such images and the appropriate places to display them.
"They are images that belong to a particular whanau," he said. "Probably the best place for that to be exhibited is to take it back to the whanau that actually whakapapa to those ancestors. Marae is the most appropriate place for them to be hung, like all the other images of our ancestors.
"So if people wanted to look at the work of Lindauer they could go to the place where those people originally come from. I think that would be a more appropriate place than hanging in an exclusive ... art gallery."
Auckland Art Gallery director Rhana Devenport said a record 99,000 people attend the gallery's recent Lindauer exhibition.
"I'm completely shocked - we're all completely shocked. Usually art crime in this country is forgery and fakes, not this sort of violent midnight robbery."
She said the theory that a descendant of one of Lindauer's subjects may be behind the raids was "inconceivable".
"I hope whoever it is returns the works as quickly possible."
Gow Langsford gallery co-founder John Gow, who formerly owned the two stolen Lindauer works, said the paintings were "incredibly important" to New Zealand.
"A good Lindauer is a very, very good painting," he said.
Lindauer was ranked alongside Goldie in terms of importance to New Zealand's art history, he said.
Gow also feared the paintings may have been damaged during the heist.
He sold the paintings 18 months ago to an undisclosed buyer, who had them displayed at the International Art Centre.
The owners of International Art Centre declined to comment.
• The Motunui panels were illegally smuggled out of New Zealand in 1973 but returned after a 40-year legal battle.
• Colin McCahon's celebrated Urewera Mural was taken by political activists in 1997 but returned the following year
• The bronze statue of Pania of the Reef was stolen from Napier's foreshore in 2005 but discovered by police in a residential property a short time later.
• Art thieves stolen a Goldie painting and a set of Colin McCahon manuscripts Crom Auckland University during the holidays in 2007. The works were eventually returned after an "elaborate deal" between police and the accused criminal.
• In 1998, Anthony Ricardo Sannd stole a $2m James Tissot painting from the Auckland Art Gallery. He was caught and imprisoned.
Defence counsel says Mark Hohua died after falling on to concrete steps while fleeing.