The cat, called Bobby Ginge, was being fostered by a woman, and, after going missing for six weeks, returned missing a paw and a lot of weight.
Remarkable Vets owner Geoff Woodhouse said a gin trap would be the ''immediate go-to for a potential cause'' but added ''there's other ways a cat could lose a paw'' such as getting caught in wire.
The affectionate ginger cat's front left leg was amputated to the armpit yesterday morning at the vet surgery.
Mr Woodhouse said the cat was recovering well and eventually ''will pretend nothing's happened'' despite the cat having suffered for what could have been weeks.
''It was not a fresh wound - he's been suffering for a while.''
The location where Bobby was injured was yet to be determined and although he was living on Queenstown's urban fringe, a cat's range can be far, he said.
''It doesn't mean that it's [the trap] definitely on the urban fringe just because a domestic cat got caught.''
In 2008 new restrictions for the use and sale of leg-hold traps came into effect.
Leg-hold traps must not be used within 150m of a dwelling without permission from the occupier or in any area where there is a probable risk of catching a pet animal.
Ministry for Primary Industries regulatory reform and animal welfare manager Colin Holden said the only leg-hold traps which could be used were size one long-spring traps, size one double-coil spring traps and size one and a-half padded-jaw, double-coil spring traps.
He suggested users check with their local authority before using any traps, check all leg-hold traps daily for trapped animals - which must be removed and properly cared for if caught - and report cases of trapped pets to the ministry or the SPCA.
Failure to comply with regulations is an offence and punishable by imprisonment and/or a fine.
The newer possum traps were far more humane, Mr Woodhouse said.
