Vietnamese customs and police are investigating a case in which Taiwanese authorities discovered 600 bricks of heroin hidden inside an air shipment sent from Vietnam.    On November 17, Taiwanese law enforcers seized a shipment of heroin with an estimated street value of $380 million at Taoyuan International Airport. The drugs were found hidden in 12 empty stereo speakers, each of which contained 50 packages of heroin, said Taiwan’s Criminal Investigation Bureau (CIB). These bricks of heroin were coated with chocolate paste in order to fool detection dogs. The narcotics were allegedly produced in Myanmar and shipped to Taiwan through Vietnam. The CIB bureau said seven people had been arrested. Of these, the main suspect is surnamed Wong, who worked for a cargo transportation company and was familiar with cargo transportation channels. According to investigators, Wong had visited Vietnam and China several times, apparently to handle the illegal drugs. Taiwanese authorities have detained seven suspects. The case was the largest seizure of drugs seen in Taiwan in two decades. Speaking with Tuoi Tre about the serious drug trafficking case, a high-ranking official at Vietnam Customs' Anti-Smuggling Investigation Department said his agency is coordinating with police to investigate the case. According to a Tuoi Tre source, the consignor of the shipment was LH Freight Forwarding Company, but as it has yet to sign a contract with China Airlines, it had KL Freight Forwarding Company, a business partner of the airline, arrange with China Airlines to send the shipment. As a result, the shipment was sent by LH through KL on a China Airlines plane at 8:05 pm on November 14. It consisted of 12 cartons weighing 400 kg in total. The case is under investigation, the official said.