Hong Kong police announced a record-breaking 700kg seizure of cocaine on Sunday, with officers suspecting the huge shipment was smuggled into the city on speedboats.

The bust is the largest in the territory in nearly a decade, netting 930 million HK dollar ($119.6 million) worth of cocaine.

Authorities say the collapse of global travel during the COVID-19 pandemic has forced smugglers to make riskier bulk shipments instead of using drug mules travelling through airports.

Police said the bust was made on Friday when officers intercepted a man with a trolley in the Fo Tan industrial district and found 150 bricks of cocaine in cardboard boxes.

Another 492 bricks were later found in an industrial building and an apartment in the same district, leading to the arrest of two men aged 19 and 25.

"We believe [the drugs] were transported via long-range shipping to waters near Hong Kong from their source area in South America and then smuggled in by illegal speedboats," senior superintendent Ng Kwok-cheung told reporters.

"We found a lot of water-proof bags that were still wet at the scene and all the cocaine bricks were carefully wrapped in plastic," he added.

Police said Hong Kong's previous record cocaine seizure was 649kg discovered by customs in 2012.