A leading expert in recovering stolen and missing art said media coverage of the recent smash and grab style theft of two high-profile paintings had left them worthless to thieves.
Chris Marinello from Art Recovery International in Italy said the two Gottfried Lindauer paintings snatched from International Art Centre in Parnell, Auckland, were now "radioactive" and no one would buy them.
Marinello, an expert who had seen more than $500 million of art recovered, said last weekend's ram-raid theft of the two paintings was amateur and opportunistic.
"This was not an elegant robbery. It was totally unsophisticated by people who thought they would be able to sell the paintings quickly," he said.
A film crew were working with Marinello as he worked through locating seven high-profile stolen works.
Marinello urged New Zealand authorities to register the Lindauer theft and details of the artworks on the Artive.org register.
He oversaw the development of the Artive.org database which is considered the most technologically advanced system in the identification of stolen art.
The paintings stolen in the Parnell ram-raid were both by Gottfried Lindauer in 1884 and were known as Chieftainess Ngatai - Raure and Chief Ngatai - Raure. They were about to be auctioned, and were estimated to be worth $1m together.
Czech-born Lindauer trained at the Academy of Fine Arts in Vienna and migrated to New Zealand in 1874.
He became one of the most prolific and best-known painters of Maori subjects along with Charles Frederick Goldie.
Marinello said there was a possibility a ransom could be demanded for the paintings' return or they could be used to access drugs or weapons or as leverage in a "get out of jail free card".
He said the theft of the well-known paintings was unlikely to be an ordered grab.
If that was the case more care would have been taken, he said.
"We are not talking about stolen to order because of the way the smash and grab was done.
Marinello said there was a market for the Lindauers overseas because they were attractive works of art and that was why the Artive.org register was so important.
If the pieces were recovered Marinello said their value would depend on damage done. The high-profile theft of James Tissot's painting Still on Top saw it plummet in value.
The work was stolen from Auckland Art Gallery in one of New Zealand's most high-profile art heists. Ricardo Sannd, also known as Ricardo Romanov, walked into Auckland Art Gallery with a gun and cut the famous work from its frame in 1998.
The painting was found under Romanov's bed a week later but was so badly damaged tiny pieces of it were found on the gallery floor for weeks.
Although it will never be sold the painting went from an estimated $8m to an insured $2m.
Marinello said some works increased in value because the theft contributed to the story.
"There was a Picasso that was stolen and the theft increased the value because it added to the colour of the work's story.
"That is not usually the case though."
Many works were rolled up, treated badly and stored in conditions vastly different to the temperature controlled environments of museums and galleries.
"They are stored under beds, hidden away because they are that hard to sell," he said.
"I had a $6m painting handed to me in a garbage bag out the window of a Mercedes."
New Zealand art expert Penelope Jackson echoed Marinello's thoughts and concerns on the Lindauers' theft.
Later in the year the gallery received a Polaroid of what was thought to be Psyche.
The photo was later revealed to be a hoax with the clever confession:
Dear Sir, Psyches sleep, Psyches awake Some are real, some are fake Masterpieces are seldom met, Touch this one, the paint is still wet.
Other recovered high-profile pieces include the 1997 theft of Colin McCahon's Urewera mural stolen from a Department of Conservation visitor centre by Tuhoe activist Te Kaha. The work was returned 15 months later after negotiations.
In 1998 the $8m James Tissot oil painting - Still on Top - was stolen by career criminal Ricardo Sannd, also known as Ricardo Romanov.
Armed with a gun Sannd stole the painting, worth $8m, from Auckland Art Gallery. It was later found hidden under his bed.
Sannd was sentenced to nearly 14 years in prison for the crime.
In 2005 the statue Pania of the Reef was stolen from the Napier foreshore. The motive was never known but Pania was discovered a month later and recovered by police. She was restored, then replaced.