Cuong, 60, is being probed for "negligence that results in serious consequences," the Ministry of Public Security stated Thursday.
The incident is the latest development in a counterfeit drug case involving Vietnam Pharma JSC (VN Pharma) and the fake drug branded Health 2000 Canada. Cuong stands accused of violations that allowed VN Pharma to import the fake drug to Vietnam.
Cuong has served as head of the Drug Administration of Vietnam since 2007, and became Deputy Minister of Health in 2016.
Previously, several high-profile figures related to the case had been probed, including former head of the Drug Administration Nguyen Viet Hung, former head of its drug registration department Pham Hong Chau and former Ho Chi Minh City Customs official Le Dinh Thanh.
Former chairman of the management board of VN Pharma Nguyen Minh Hung and former director of H&C International Maritime Trading Co Ltd Vo Manh Cuong were deemed masterminds of the case and also investigated.
According to case files, Hung and Vo Manh Cuong had made a deal to purchase 838,000 packets of the fake drug Health 2000 Canada, worth over VND54 billion ($2.3 million), for import to Vietnam.
Both Hung and Cuong adapted the drug’s info, price and logo to fool authorities. The People’s Court of HCMC in 2019 sentenced Cuong to 20 years and Hung to 17 years in jail for their crime.