The 229 kilograms of heroin on board a Taiwan-bound plane went undetected at Tan Son Nhat International Airport on November 16 because the consignment was sent through a channel that does not subject goods to scrutiny, a customs official said.
Tran Ma Thong, deputy chief of the Ho Chi Minh City Customs Department, told the press Monday that customs officers had fulfilled standard protocols.
He said that the department is still waiting for investigation results.
According to the official, the 500-kilogram consignment allegedly containing 12 empty stereo speakers went through the Green Channel, which is for goods within customs' limits.
Goods going through the Green Channel are not subject to checks such as scanners, he said.
"Customs officers just checked the information in the customs declaration form and cleared the consignment," he added.
On November 15, Tan Son Nhat Cargo Services Co. Ltd (TCS), which provides cargo handling services for international flights transferring out of Tan Son Nhat airport, signed a contract with the Le Hoa Trading and Forwarding Co. Ltd to send the consignment to Taiwan.
TCS is a joint venture between Vietnam Airlines, Southern Airports Services Company (SASCO) and Singapore Airport Terminal Services (SATS).
Le Hoa previously signed a contract with Air Sea WorldWide Vietnam Logistics Co. Ltd in HCMC to send the consignment.
Its partner booked the shipment with Korchina Logistics Co. Ltd, a representative of China Airlines in Vietnam.
After clearing customs, the consignment was designated as "magnetic" and labeled "dangerous" by security authorities of the airport.
A Le Hoa representative was quoted as saying that the company did not own the narcotics, but was contracted to send the shipment.
The representative refused to reveal the owner's identity as the investigation is ongoing.
On November 17, Taiwan's Criminal Investigation Bureau (CIB) seized 600 bricks of heroin, which were found hidden in the stereo speakers.
The drugs had been smeared with chocolate to avoid being detected by dogs, the bureau said.
According to the bureau's estimate, 229 kg of heroin is worth $300 million.
Taiwanese authorities said it was the nation's largest heroin smuggling bust in two decades.
The CIB said seven people have been arrested.
A suspect surnamed Wong, who worked for a transportation company, visited Vietnam and China several times, apparently to handle the illegal drugs, investigators said.
The bureau added that they had been monitoring Wong along with others suspected of being involved in heroin smuggling.
It said that Taiwanese suspects who reside in China had directed Wong and his accomplices.
On November 27, Vu Hai Thanh, TCS director, declined to comment when approached by Thanh Nien.
However, an airline official, who wished to remain anonymous, said the incident would severely tarnish the Vietnamese aviation sector's reputation.
Vietnamese authorities should seriously review the question of aviation security and safety, he said.
Thong, the customs officia, said Monday that after the heroin haul was busted, Taiwanese authorities did not contact the HCMC Customs Department nor reply after the department asked for more information regarding the case.
"We are still figuring out why they did not ask us for our cooperation despite the fact that they had been monitoring the gang for a while.
"Maybe they had been investigating secretly."
Last week, the four officers with the Aviation Security Center at Tan Son Nhat airport who were in charge of scanning cargos (after they cleared customs) were suspended for failing to detect the heroin haul.