It's only a guess, but there could be piles of Lindauer paintings languishing in Northland sheds and other storage spaces.
Or, perhaps the "print" of a moko-wearing Maori chief or kuia that has hung in the hallway for decades isn't a print at all, but an original painting.
Northland residents are being urged to check they haven't got any valuable paintings by 19th century Czech artist Gottfried Lindauer lying around.
The Auckland Art Gallery is appealing to the public to help uncover Maori and Pakeha portraits by the artist, with art historians estimating there are more than 100 original paintings by the prolific portraitist yet to be discovered. While many Lindauer paintings are national treasures that document an important period in New Zealand's history, the picture is not yet finished.
Lindauer is thought to have painted up to 30 versions of the famous portrait known as Heeni Hirini and Child, for instance, said Auckland Art Gallery's curator of Maori art, Nigel Borell.
Mr Borell said he is aware of 12 paintings of that subject alone, but would like to find more Lindauer works. Uncovering further originals would be significant for New Zealand art historians, tribal descendants and cultural historians.
"We want to piece together the puzzle of Lindauer's prolific painting career to learn more about him," he said.
Another mystery concerns portraits of Lindauer's patrons: Sir Walter Buller and Henry Partridge. Both men commissioned the artist to paint many portraits, including portraits of themselves, however the whereabouts of both portraits is unknown. Among Lindauer's Northland/Tai Tokerau subjects were Tamati Waka Nene (Ngapuhi) and Paratene Te Manu (Paratene).