Australian sales of vitamin group Swisse plunged 27 per cent in the nine months to September as Chinese resellers fled the market following changes to China's e-commerce laws in January.

Not even the star power of Chris Hemsworth, Nicole Kidman and tennis player Alex de Minaur was enough to blunt the exit of many smaller daigou operators, which previously bought large volumes from retailers such as Chemist Warehouse and then resold them online in China.