Hong Kong customs uncover $33M cocaine stash hidden 36 feet below sea level

What looked like an ordinary cargo ship passing through Hong Kong waters was, in fact, hiding a secret far below the surface.

Last month, Hong Kong customs officers uncovered an extraordinary drug smuggling operation after discovering hundreds of millions of dollars’ worth of suspected cocaine concealed deep beneath the waterline of a massive freighter — the first case of its kind ever detected in the city.

Acting on intelligence shared by mainland Chinese authorities, officers turned to underwater robotic technology when an initial search of the ship came up empty. That decision proved crucial. The robots revealed 11 tightly wrapped packages of suspected cocaine, weighing a total of about 417 kilograms and valued at HK$256 million (US$32.9 million), hidden inside a little-known part of the vessel called a “sea chest.”

A sea chest is not a place anyone would normally think to look. Built into the ship’s hull and sitting around 11 metres below sea level, it is designed to draw in seawater to cool engines and power onboard systems — not to store drugs.

“Concealing drugs under a vessel is extremely rare,” said Lau Yuk-lung, head of customs’ Drug Investigation Bureau. “The opening is very narrow and completely underwater. We believe only professional divers could have accessed it.”

Investigators say the smugglers likely chose the spot precisely because it seemed impossible to reach — and even harder to detect.

The sheer size of the ship added to the challenge. Stretching 333 metres long and 48 metres wide, the vessel had travelled from Brazil, stopped in Singapore, and arrived in Hong Kong on November 4. It was meant to continue on to Shanghai and Ningbo, raising concerns that the drugs were intended for distribution across multiple destinations.

“We cannot rule out the possibility that the ship was being used as a floating drug warehouse,” Lau said. “By intercepting it here, we cut off the entire supply in one operation.”

Two crew members, aged 45 and 37, were arrested during the operation and later released pending further investigation. Both are Indian nationals, according to sources, and customs officials say further arrests remain possible.

The case began quietly, with officers analysing shipping routes, vessel designs and intelligence suggesting drug syndicates were moving away from hiding narcotics among cargo and instead using concealed compartments on freighters. After the ship was targeted and searched at Tsing Yi with no immediate results, officers took the unusual step of deploying underwater robots.

Those robots detected suspicious, waterproof-wrapped packages wedged behind a metal grate in one of the ship’s two sea chests. Divers were then sent down to inspect the compartment firsthand, working against strong currents and high tides.

Inside the 12-cubic-metre space, officers recovered 11 packages weighing between 30kg and 45kg each. Lead blocks had been attached to the packages — a calculated move believed to counter the powerful suction created as seawater is drawn into the ship.

For customs officials, the case marked a milestone. Lo Chin-man, head of marine enforcement at the ports and maritime command, said it was the first time underwater robots had played a decisive role in cracking a smuggling case in Hong Kong.

“The robots performed exceptionally well in strong currents and greatly improved officer safety,” he said, adding that customs would continue to invest in advanced technology.

Under Hong Kong law, anyone convicted of trafficking dangerous drugs faces a maximum penalty of a HK$5 million fine and life imprisonment — a reminder of the high stakes beneath the surface of this unprecedented case.