Dylan Swain, from the Wildlife Enforcement Group told Radio New Zealand they were in the process of working out which pieces of ivory were illegal and which were allowed to be in the country.
He was unable to say whether the man had permits for any of the seized items.
"(If guilty of illegal possession) he potentially faces up to five years in prison and or a fine of up to $100,000."
Mr Swain said illegal possession is considered extremely serious, particularly given the extinction threat to many elephants in Africa and Asia.
He said people can order the ivory over the internet and it can be missed at mail sorting centres.
"Most mail screening is targeted at drugs and objectionable material.
"It is unusual for items such as ivory to arrive in such a manner and I think it caught some of our staff unawares."
He said the item was x-rayed and identified by its shape as being a possible tusk.
"That is another reason why some of the other pieces have managed to get through because they are smaller items that are not what would be considered tusk-shaped and so the staff x-rays wouldn't pick those up."
A ban on trading ivory has been in place since 1989 in 175 countries, including New Zealand.
