Customs officials in Singapore uncovered a shipment of 1.8 tonnes of ivory, with a value of around $US2.5 million.
The consignment, marked as being waste paper, was from Africa.
Elephant poaching is on the rise because of demand from Asia, where ivory is used for ornaments and in traditional medicine. An estimated 25,000 elephants were killed in Africa in 2011.
The Quarantine & Inspection Department said on Wednesday that 1099 pieces of raw tusk were found in 65 sacks after a tip-off.
The statement did not say where the shipment was heading after Singapore.
The BBC reports trading of ivory is illegal under the Convention on International Trade in Endangered Species.
In 2002, six tonnes of ivory were seized in Singapore. It was traced to Kenya where it was eventually returned.