Ivy from a Polish castle was transported in a less than regal manner after biosecurity dogs sniffed out the plants allegedly hidden in a Polish gardener's underpants.
Ministry for Primary Industries staff found plant cuttings, a bulb, a tuber and seeds after the man arrived on a flight at Auckland Airport on Saturday, the ministry's northern border clearance manager Craig Hughes said.
MPI strip-searched the passenger after a biosecurity detector dog sniffed out the plants near the man's groin.
A Customs drug dog had also indicated the man was carrying something in his pants.
The man, a New Zealand resident, was wearing two pairs of underpants and the itchy concealment included ivy from a castle in Poland, Mr Hughes said.
"He wanted the plants for his garden, saying he could not find them in New Zealand."
The case has been referred to MPI investigators and the man was likely to be prosecuted under the Biosecurity Act.
"We have zero tolerance towards this type of behaviour, which could endanger New Zealand's primary industries and native plant life by introducing foreign pests and diseases."