An international art crime expert says it's unlikely police will find the perpetrators of the sophisticated swindle of two Gottfried Lindauer paintings.
It's been more than three months since the paintings, worth $1 million, were grabbed from the International Art Centre in Parnell by brazen thieves who rammed a window before making off with two portraits - Chieftainess Ngatai-Raure and Chief Ngatai-Raure - ahead of their auction.
Police earlier described the heist as well planned. Two men in a stolen vehicle are believed to have sprayed the window with a weakening compound before ramming it twice.
Two men were caught on security camera, before escaping in a white Holden Commodore with fake license plates, driven by a third person. The other vehicle was abandoned.
Detectives released footage of the Commodore, and security images of two men outside the gallery at the time, and Interpol and Customs were notified.
A Customs spokesperson this week said it wasn't alerted to the art heist until the evening of April 1- giving thieves ample time to board a plane without raising suspicion.
Experts spoken to agreed it wouldn't have been difficult for thieves to smuggle the works out of the country, either by rolling them up into a suitcase, or shipping them and labelling them as generic freight.
The earliest international flights out of Auckland after the 4am raid were 6.30am departures to Australia and Fiji, followed by an 8am to Hong Kong, an 8.45am to Korea, and a 9am to Tokyo.
Customs said it wasn't contacted by police until that Saturday evening. The exact time couldn't be verified.
"Police requested Customs to be on the lookout for passengers carrying or exporting paintings," the spokesperson said.
"Alerts were created in our system and a notification sent to all Customs ports to be on the lookout for the stolen paintings."
Detective Inspector Scott Beard declined to comment on the investigation, except to say he didn't believe the time Customs was alerted affected the investigation in any way.
He declined to confirm whether the people in security footage had been identified. The last public update on the investigation was months ago.
Christopher Marinello, an expert on art recovery based in Italy, wasn't optimistic the thieves would be caught, but believed the works could still be recovered.
"I am confident the paintings will surface," he said.
"When the thief realises he or she can't sell the pictures for their true value, they will be traded or sold at a fraction of their worth until some poor soul not doing any sort of due diligence decides to take a chance on making some money on the paintings.
"We might get lucky and trace the chain to the actual thief but the more time that goes by, there is less chance of this happening."
Experts have theorised the culprits are anywhere from naive opportunists, activists, gang members, or international underworld figures.
Previous high profile art thefts included Anthony Ricardo Sannd's brazen snatch and grab of a million-dollar Tissot, which he cut from its frame and stashed under his bed, and activists' seizure of Colin McCahon's Urewera Mural. Negotiations lead to its return the following year.
University of Auckland art history lecturer Ngarino Ellis said too much time had gone by for it to be likely that thieves were planning a ransom.
"They've lost their window of opportunity - when everyone is on tenterhooks," she said.
"The New Zealand police are tenacious and because it's such a high profile heist, and it stung at the heart of most New Zealanders, they're more likely to solve the crime (but) it might not be today or tomorrow."
She said the value of Lindauers would "absolutely" have increased since the heist. Just days after ward a Dunbar Sloane auction sold one for a record $227,000.
Last year Auckland Art Gallery put a call out for Lindauers, as part of an online project cataloguing his works. Maori art curator Nigel Borrell said Lindauer was a prolific painter, and estimated there were hundreds of his works in private New Zealand collections, and overseas.
The then renewed interest in his paintings, an international demand for the unique colonial style, and comparisons of Lindauer to Charles Goldie, would be enough to pique the interest of a would-be criminal, he said.
He believed the works were damaged in the theft, and intense media and police scrutiny would have "ham strung" the thieves.
"They probably don't know quite what to do with them, if they still have them. They'll be in a very odd space with what to do with them (because the paintings) are being watched very closely."
International Art Centre director Richard Thomson said he had "every bit of faith" in police.
"Our security was second to none quite frankly but some subtle changes have been made and those are not up for discussion under any circumstances," he said.
"The police may choose to fill you in on how complex this particular incident was. As far as running the business, we were open on the day of the raid and have been every day since. We are the go-to institution for the resale of national art treasures so it's business as usual."
• Has anyone identified the two men in the security images?
• Were more than three people were involved?
• How closely were borders monitored in the ensuing day?
• Are the paintings still in the country?
• What was the motivation?
• Could the paintings have been smuggled onto a plane?
• Who did the stolen car belong to?