Police in the central province of Thua Thien-Hue Hue said Monday they had seized 40 kilograms of marijuana smuggled in from Laos.
Police said it was the biggest pot bust in province history.
Last Friday, police arrested the mastermind To Huu Huy, 36, and his three accomplices: Huy’s father To Huu Tien, 60, and two family members Ho Dang Tuan, 44, and Ho Dang Dieu, 23.
A police source said that they began noticing smugglers coming through the Lao Bao Border Gate in neighboring Quang Tri Province in February.
After some surveillance, police determined that Huy sold the marijuana to other dealers across the central region including in Da Nang City.
A task force secretly followed Huy on September 6 after he brought money into Laos to purchase a shipment.
Police say he bought the marijuana on the night of September 8 from a Lao kingpin for around VND700 million (US$33,000).
Tuan then transported the drug to Vietnam in a truck loaded with charcoal and firewood.
Some officers followed the truck while other kept tabs on Huy.
Tuan arrived at a cement factory in the province early last Friday and called Huy to pick up the drugs.
Huy immediately showed up with his father. The pair were caught red-handed.
The group has allegedly smuggled 60 kilograms of marijuana from Laos into Hue.
Police are investigating further.
Marijuana is treated as an addictive substance under Vietnamese law and remains banned all over the country.