A 36-year-old woman and 58-year-old man have been arrested for trafficking 6kgs of 'ice' worth $2.1 million, the largest seizure of the drug at the airport in three years.

The Hong Kong pair were arrested as they were about to fly to New Zealand Monday. Aviation Security Company staff found six bags of the drug, weighing about 3kgs, in a specially-designed vest worn by the woman. The rest of the haul was found on the man, concealed in a similar fashion.

The case is being investigated by Customs' Airport Investigation Division, and cocaine, cannabis and some apparatus for drug abuse, has been found in the woman's home.