Phil Wheeler, a former pupil of Rotary Park School, has spent two weekends scouring the school grounds with a metal detector in the hope of recovering what he believes to be a tin time capsule.
"If it is plastic, we are [out of luck]."
In the mid-1980s, the senior classes of the-then new school wrote about themselves and what they thought the future would be like, before placing their work in the capsule which was buried.
However, the former principal who buried the time capsule could no longer remember its exact location, nor could former pupils, Mr Wheeler said.
With permission to search the grounds, he hired a metal detector but rather than locating the time capsule ended up leaving "gopher holes".
"Rotary Park has had a tough time in the press lately, and it is a great school and a lot of the old [pupils] had a real fondness for it . . . so when we found out Hekia Parata hoped to close the place, it would be a real appropriate time to see if we can find it, and to give some sort of context around the life of the school."
Mr Wheeler said he believed those in the-then standard four year at the school in 1985-86 may have watched the time capsule being buried, and he was appealing for anyone with information to contact him.