I've been digging around in the microfilm archives and dug up stuff about the various versions of "The Game" participatory theatre event / pseudolarp which ran in Christchurch in the early 1990s
That's an ad for the 1990 version, which ran as part of the 1990 youth festival. According to news reports it involved a cast of 80, who used a network of tunnels and hidden passages around the Christchurch Arts Centre. The event's creator, John Hudson, was influenced by Commedia Della'arte and theatresports.
They ran another version in Whangarei in early 1991 (there's a review in Pacific Way which I'm trying to get my hands on), and in Christchurch in early July 1991. That run was shut down after 4 days due to the sets not complying with building regulations.
There was also a 1992 run which used a cast of 35 actors and modified the inside of the old Cinerama theatre. A bunch of KAOS people went along to this one. Playwise, it was a tunnel of fun: you enter, you wander round, and in theory you try and get all the boxes on your card ticked so you can escape. So not really a larp, but definitely related.