Taichung law enforcement authorities seized 20kg of heroin in a cargo of scrap metal at Taichung Harbor and arrested three suspects on Saturday.
The Ministry of Justice's Investigation Bureau said in a press statement that the heroin had a street value of approximately NT$200 million (US$6 million).
The bureau said its agents had been tracking the main suspect, Hung Chao-pin (洪朝彬), as he prepared to smuggle the drug from Thailand.
The bureau said it had been cooperating with US and Thai drug enforcement authorities.
Hung allegedly sent two men, surnamed Chiu and Chi, to Thailand earlier this month to arrange for the transportation of the drug.
Officials said the heroin, which was hidden inside 52 iron pipes, left Thailand on Jan. 19.
The bureau knew the cargo ship carrying the drug would dock at Taichung Harbor on Saturday, and investigators swooped to arrest Hung and two other suspects at Hung's residence in Changhua and took them to inspect the ship's cargo.
The bureau said Hung ran a company importing iron and sand and that its operations were used as a cover for the smuggling.
Hung was previously arrested in 1994 for smuggling heroin, but was released on a technicality when the Kaohsiung District Court declared a mistrial.