The Drug Crime Investigation Department under Vietnam's Ministry of Public Security said Sunday that it was treating the case in which groups of Chinese people were found manufacturing drugs in the central and Central Highlands regions as "serious," and collaborating with Chinese police to investigate it further.

Vietnamese police detained seven Chinese men and one Vietnamese man for investigation last week.

The leader of the ring has been identified as Cai Zi Li, 56, who has a record of previous drug crimes in China. He had been sentenced to life and let out under an amnesty program not long ago.

The illegal activity was discovered at the Dong An Vien Export-Import Company factory in the Central Highlands province of Kon Tum on August 6.

Colonel Vu Van Hau, deputy director of the Drug Crime Investigation Department, said last week that Vietnam had busted several drug manufacturing rings run by its citizens, but this was the first time the country has unearthed one run by foreigners.

The factory in Kon Tum is owned by a Vietnamese person. The Chinese men had rented it to make illegal drugs. 140 liters of drug precursors, 13 tons of chemicals, and 20 tons of machinery and equipment were seized.

Tests found that the chemicals were used as materials for making methamphetamine.

Last Wednesday, police busted a warehouse in Binh Dinh Province in central Vietnam and found hundreds of barrels and bags of chemical substances that were also identified later as ingredients for cooking meth.

It was further confirmed that the warehouse was also operated by the same ring run by Cai Zi Li in Kon Tum.

Barrels containing chemicals for producing drugs are seized by police in the central
province of Binh Dinh, September 11, 2019. Photo by VnExpress/Tram Anh.

Vietnamese police have found out so far that the ring chose Vietnamese firms with their own facilities outside downtown areas reachable by just one path.

Members of the ring then tricked those firms by hiring their facilities saying that they needed a place to test a production chain to make pesticides and rat poison. If the project was found feasible, they would sign a deal with those companies to make products in Vietnam.

So far, in investigating the drug ring, which has roots in China, Chinese police have summoned 22 people and decided to arrest 18 of them.

In the first nine months of this year, Vietnam dealt with more than 20,200 drug cases, arrested more than 31,500 people, and seized one ton of heroin, 760 kilograms of marijuana and neary six tons of synthetic drugs.

The country has some 250,000 registered addicts, but the actual figures are thought to be much higher.

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