A new wave of infections since late April has forced the country to impose movement restrictions in a third of its cities and provinces, many of which require people to have negative certificates to move around.
Tran Tuan Duong, who runs a printing business in Bac Ninh province, was arrested on Wednesday while selling six certificates to a client for 1 million dong ($43.86), the provincial police department said.
Duong, 34, confessed to police that he had sold around 150 such documents, including ones for swab-based polymerase chain reaction (PCR) tests, according to a police statement on Thursday, which said further investigation was underway.
Vietnam has recorded more than 241,000 coronavirus infections and at least 4,487 deaths overall, with the vast majority of those in recent months, which followed a year of successful containment. ($1 = 22,800 dong)