Alongside her day job, accountant Jane Li runs a lucrative export business. A recent Chinese migrant to Sydney, she sells baby formula and other products to a network of friends and acquaintances back home who pay a mark-up of up to 50 per cent for products from the trusted shelves of foreign supermarkets.

One of a group estimated to number more than 100,000 in Australia, Ms Li is a “daigou” or “buyer on behalf”.

This “suitcase trade” in luxury and health goods has become a global phenomenon, accounting for Rmb34bn-Rmb50bn ($5bn-$7.5bn) globally in sales last year, says consultancy Bain & Co. It has thrived because of the relatively higher cost of these products in China, a perception that western brands have higher safety standards following a string of food scandals in China, and a surge in interest among middle-class Chinese consumers for products perceived to feed a healthier lifestyle.