Vang Lien Hoa, 22, was arrested by dozens of police officers while driving towards Muong Khuong Town, which borders China.

Two bags containing around 250,000 pills of synthetic drug were confiscated from the vehicle.

"This is the largest amount of drugs ever found in the province," said a representative of the Lao Cai anti-narcotic department.

Hoa said a person in China had contacted him last week, offering him VND100 million ($4,306) to deliver the drugs.

On Wednesday night, Hoa drove his pickup to a local commune along the border to receive the shipment, before driving them to Muong Khuong and eventually China. He was arrested en route.

Hoa was accused to be part of a transnational drug trafficking ring that used Vietnam as a hub, authorities said.

Vietnam is a key trafficking hotspot for narcotics from the Golden Triangle, an intersection of Laos, Thailand and Myanmar and the world's second largest drug producing area after the Golden Crescent in South Asia.

From Vietnam, the drugs are taken to Taiwan, the Philippines, Malaysia, South Korea and even Europe, Australia and Latin America.