Customs officials have made its largest methamphetamine trafficking bust in Hong Kong's history, seizing a HK$1.1 billion haul of the suspected drug in Kwai Chung.

Officials on Saturday said 1.8 tonnes of suspected liquid meth had been concealed in a consignment labelled as coconut water, en route from Mexico to Australia, via Hong Kong.

Fong Heung-wing, from the Customs Department's drug investigation bureau, said intelligence reports had indicated that a large amount of meth would be passing through the city.

He added that the shipment, which came alongside other goods, had raised suspicions, as it was unusual to have cargoes of coconut water from Mexico.

Upon inspection at the cargo examination compound last Sunday, officers said they discovered the liquid meth.

So far, no arrests have been made in Hong Kong, but customs officers said they believed a transnational syndicate was behind the operation, and were working with overseas authorities.