Hong Kong has made its biggest-ever seizure of methamphetamine after uncovering a shipment arriving from Mexico worth more than HK$1 billion ($130 million), authorities said Saturday.

Customs officials found a record-breaking 1.8 tons of liquid meth hidden in cartons of coconut water en route to Australia.

The shipment, which officials said likely involved a massive international drug trafficking ring, comes as the Chinese finance hub sees a rise in drug busts involving meth.

"We believe the liquid meth, of high purity, came from South America. It was packaged there and shipped via a convoluted route to Hong Kong, to be sent to Australia," said senior superintendent Lee Ka-ming, head of the drug investigation bureau at Hong Kong customs.

Arrests were not made. Hong Kong has so far this year uncovered more than double the meth seized in the whole of last year, with almost three tons confiscated by authorities.

The latest bust came days after law enforcement seized meth worth $5.9 million hidden in electrical transformers, which was also headed for Australia.

Hong Kong authorities were alerted via intelligence exchanges with overseas law enforcement about large liquid meth shipments arriving in the city, customs official Fong Heung-wing told reporters.

"Coconut water (shipments) from Mexico are extremely rare… the last time was in 2016 and weighed just six kilograms," Fong said, adding that the size of the shipment also made it suspicious.

The contraband was found among other goods in a cargo container and identified using X-rays last Sunday.

An online search for the shipment's alleged recipient, an Australian company, came up empty, officials said.

The previous largest meth bust in Hong Kong came in April when officials found 700 kilograms of the drug hidden in industrial equipment from Mexico.