The SPCA suspects banned animal leg-hold traps are to blame for the deaths of two cats and injuries of another in central Auckland.
It said that over the last 18 months, one cat was found with its spine crushed, one with a severed tail and another with a foot missing.
Leg-hold traps are spring operated metal jaws that clamp onto the animal's legs, and are illegal in urban areas.
SPCA Inspector Mellisa Rush said they do not want to see any more animals injured or killed by these traps.
"SPCA wants to remind our community: don't set leg-hold traps in urban areas. The risks to pets are real and we don't want to see anymore animals injured - or possibly killed - by this," she said.
"Injured cats have been reported on Mount Albert Road and Columbia Road. Our Inspectorate is warning pet owners in this area to watch out for leg-hold traps. Anyone who discovers one of these traps, or an animal who has been caught in one, should contact SPCA immediately."
The SPCA is urging anyone who discovers such traps to contact them.
Separately, Sandringham residents living near Eden Park reported five cats missing in March.