A passenger from Malaysia declared a dried cowpat to Ministry for Primary Industries staff at Auckland Airport.
The discovery last week has been described by the government agency as one of the most unusual interceptions of the summer.
It had been brought into New Zealand for burning at a Hindu temple at Otahuhu, said Dave Sims, MPI Auckland Airport manager.
"Cowpats are made by mixing fresh cow faeces with hay. We can't permit them to enter New Zealand as they could contain unwanted seeds, parasites or even plant or animal diseases that could harm the livelihood of farmers and growers."
Cowpats have been used for centuries to light fires in India.
Mr Sims said it was rare for MPI to intercept cowpats, but they may become more common in the future.
"Cowspats are now a commercial product. There's even a website selling them and some customers want gift wrapping.
"The great thing in this case is the passenger declared the pat. They did everything we asked to safeguard New Zealand's biosecurity."