Customs officers have arrested four men after seizing 53 kilos of suspected heroin at Hong Kong International Airport. They say the drugs, which were hidden in packs of coffee powder, have an estimated street value of nearly HK$50 million.

Customs say the drugs had arrived in an air consignment from Thailand on Thursday, which the sender had declared as containing vegetables. The 37 coffee powder packs, which contained the heroin, were found in three of the consignment's cartons. Officers then arrested a 36-year-old man before mounting a follow-up operation in Kowloon City, bringing in a 39-year-old man.

On Friday, they mounted a controlled delivery operation in Kwun Tong, arresting two men aged 21 and 43.

Customs said investigations were ongoing.