The gallery's Curator of Maori Art Nigel Borell said many more paintings had yet to surface and finding the missing artworks would help further research for an extensive exhibition about the artist.
Although some of Lindauer's portraits have perished in fires, some had been given away in disrepair and others had been misplaced.
"We want to piece together the puzzle of Lindauer's prolific painting career to learn more about him," said Borell.
"These Lindauer artworks could be sitting on mantelpieces, in marae meetinghouses, forgotten under beds or at grandparents' houses around the country."
He said it would give the gallery a good gauge of just how many portraits still existed.
One portrait, known as Heeni Hirini and Child was estimated to have been painted up to 30 times.
Borell said he was aware of 12 versions but would like to find more, to "substantiate the estimation and build a more accurate picture of this fascinating painter".
Another mystery surrounded the lost 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 their portraits remained unknown.
Borell said uncovering further examples of original Lindauer paintings would be extremely significant for New Zealand art historians, tribal descendants and cultural historians.
If you think you have a Lindauer painting or have information on the whereabouts of an original Lindauer artwork contact hello@aucklandartgallery.com