Fresh crow and squirrel legs and feathers were sniffed out at the border by a biosecurity dog.
The gory discovery was made at Auckland's International Mail Centre in a package arriving last week from the United Kingdom.
It had been labelled as craft jewellery, but that didn't fool biosecurity detector beagle Clawson, who sniffed out the illegal goods on the mail belt.
"It was a great interception for Clawson," Ministry for Primary Industries detection technology manager, Brett Hickman.
"The items posed severe biosecurity risk to New Zealand. The untreated feathers and flesh could have contained diseases such as avian flu, or unwanted hitchhikers like ticks or mites.
"We sometimes come across animal hides brought into New Zealand as ornaments, but they are normally commercially treated. To come across something this fresh with the bone exposed is very rare."
MPI will not release the package unless the intended recipient pays for treatment within 28 days.
"If we don't hear anything, it will be destroyed," said Hickman.
"We're hoping the person who was supposed to receive the package will alert friends and family overseas about our strict biosecurity rules, which are intended to protect New Zealand from foreign pests and diseases."
Four-year-old Clawson has been working for MPI for three years.