The grenade was intercepted in the post, police spokesman Michael Woods told NZPA.
"There was nothing sinister in it. It had been hollowed out and filled in, and was being sent to someone who collects these sorts of things.
"It was completely inert. We evacuated the mail centre for about an hour yesterday which is standard procedure," Mr Woods said.
The bomb squad was called about 10:30am yesterday and the package was removed to be examined, Northern police communications Inspector Matt Rogers said.
It was handed over to the armed forces explosives ordnance disposal team.
The mail centre is some way away from the main airport and flights were not affected.
NZPA
source: newshub archive
