A man's been arrested for trying to smuggle plants into New Zealand in his underpants.

Ministry for Primary Industries staff strip-searched him at Auckland airport on Saturday after a detector dog sniffed out the plants near the man's groin.

They found plant cuttings, a bulb, a tuber and seeds in his undies.

The Polish gardener - who's a New Zealand resident - told biosecurity he wanted the plants for his garden, because he couldn't find them in New Zealand.

He now faces prosecution.