Hong Kong and Japanese police have arrested four people and seized 24kg of 'ice' worth $90 million in a joint operation against a regional drug trafficking syndicate.

On July 12 Japanese police seized the drugs from a container delivered to Osaka from Canada based on intelligence provided by Hong Kong Police. They arrested three Hong Kong men aged 39 to 49 for drug trafficking. One of them, aged 49, is believed to be the syndicate mastermind. His 34-year-old wife was arrested on the same day in Hong Kong for money laundering.

Police have since frozen four properties, bank accounts and other assets worth about $17.5 million in the names of the mastermind and his wife.

About 15 million yen (about $940,000), a pistol and 10 bullets were also seized.