Suspected mephedrone seized in Belfast with a street value of £75,000 had been imported from China, the High Court has heard.
The drugs, found in packages posted to an address in Co Down, could have been originally bought for as little as £3,000, it was claimed.
Prosecutors alleged that an organised gang was involved in bringing in the consignment, found in a car which was stopped and searched on June 1.
Details emerged as bail was refused to a man accused of being a key member of the suspected plot.
Joseph Corner (51), of Clifton Drive, Belfast, denies charges of possessing class B drugs with intent to supply, importing drugs, and conspiracy to supply mephedrone.