Almost 5kg of the Class A drug was then found in a black suitcase.
The woman will appear in the Manukau District Court on Friday on drug smuggling-related charges.
Customs investigations manager Bruce Berry said the agency used intelligence to identify the woman as an allegedly high-risk passenger.
"Further questioning and a search by frontline officers at the airport indicated that something was not right," he said.
"Customs' work is led by intelligence and we do extensive screening to identify those that may pose a risk."
Berry said Customs' profiling works across the different types of drug commodities and risk countries, whatever they are.
"This seizure is yet another example of a significant amount of harmful drugs that has been kept off New Zealand's streets."
