Taiwan authorities have arrested three people and seized nearly half a tonne of narcotics in their biggest drugs bust in 10 years, according to local media.

Investigation Bureau agents and police discovered the 434 kilograms (955 pounds) of amphetamines and ketamine hidden among 1.5 tonnes of mushrooms in a container flown into Taoyuan International Airport, outside Taipei, from China via Hong Kong, the Taipei-based China Times reported.

The haul was valued at around Tw$500 million ($17 million), the biggest haul of drugs by value in a decade, it said.

Alleged smuggling ring leader Chiang Pai-li, 53 and a married couple operating a customs brokerage firm were arrested Saturday.

The ring might have used the same method to smuggle in narcotics, investigation agents said, adding that they were also probing if any customs officials were involved.

No investigation agents or police could be reached for comment Sunday.