An extensive search of Rangitoto and Motutapu islands in the Hauraki Gulf has found no sign of a cat, the Department of Conservation says.
Two people reported seeting a black cat on the shoreline at Islington Bay, which connects the islands.
Cats eat native birds, bats, lizards, and weta and other native insects, and Rangitoto and Motutapu have been free of predators and pests since 2011.
DOC spokesman Keith Gell says two predator detection dogs and their handler began looking for the cat on February 8.
He says the team searched for more than 10 days in a row without finding signs of the feline.
Motion sensitive cameras set up at Islington Bay also produced no evidence.
Gell says the team has left the islands and the operation has been scaled down, and thanked those who reported seeing the cat.
"We need to hear from the public if they see a cat or a dog on a pest-free island in the Hauraki Gulf."
There are 44 pest-free islands over 5ha in the gulf.