Customs officials said on Monday they had seized more than 400 kilograms of cocaine "skilfully" disguised as white wine by a drug syndicate.

The drugs were hidden in hundreds of boxes of drinks, including white wine and grape juice, in a suspicious container that arrived at the Kwai Chung Terminal last month.

Lui Chi Tak, head of the Customs Ports Control Group, said it was their biggest ever seizure of liquid cocaine, which has a street value of HK$490 million.

"More than 700 boxes of beverages were found in the container, 37 of which contained drugs, accounting for about five per cent of the total cargo," he said.

"The officers not only compared the packaging and weight of each box, but also meticulously examined every detail of the packaging. We also have to extract liquids and carry out various tests, including using different drug test kits."

Two men were arrested during the operation.