More than 1,000 elephant tusks and eight tonnes of pangolin scales have been found in a haul worth about £6m.
The contents were seized from a shipping container in Hong Kong on Friday, officials said.
The illegal items had been transport from Nigeria and those responsible claimed it was carrying beef, but it was searched after a tip-off.
It is the city's largest ever pangolin scale seizure and third largest ivory seizure. Scientists estimate the haul to represent the deaths of around 500 African elephants and up to 13,833 African pangolins
Two arrests have been made following the discover.
The pangolin scales are said to have medicinal value in parts of Asia and can be sold for huge sums.
Within the haul, officials said customs officers seized 8,300kg of pangolin scales and 2,100kg of ivory tusks.
They added that the shipment, which was bound for Vietnam, was "a record quantity for a seizure of pangolin scales".
