Evil Eva and her cronies threaten to blow their enemies sky-high by reactivating the Rangitoto volcano with a nuclear device.
Ardvaark Endeavour Productions - 49 min.
Cast: Melissa Donaldson, Peter Shand, Aaron Donaldson, Jon Gadsby, Nevan Rowe, Ian Watkin, Michael Wilson, Ian Mune, Clyde Scott, Jim Coates.
Screenplay: Keith Aberdein, Ian Mune;
Photography: Graeme Cowley;
Editor: Mike Horton;
Producer: John Barnett;
Director: Roger Donaldson.
I'm guessing that this was made for TV with its short duration, and I'm sure that's where I saw it.
Released on VHS back in the 1980s so yo might find a copy on an auction site