"The bomb squad then came out and did a whole assessment of the grenade, before they determined that it was in fact an inert training grenade."
Spitaels said since the discovery they'd learnt there had been a number of army training camps held around the Matamata area, which is probably how the grenade had ended up in the field.
He said potatoes had been processed at the site over the last 30 years, with about 250 tonnes of the crop being handled each day, but this was the first discovery of its kind.
"It's not an uncommon occurrence and the European factories you know, given the two world wars that we fought around it, but yeah, it was really unusual. "
- RNZ