China has arrested the head of a ring that passed off a mixture of saline solution and mineral water as COVID-19 vaccine.

The man, identified till now only as Kong, had smuggled a batch of the fake vaccine overseas although it is unclear where they were sent. He had studied the packaging of vaccines and made at least 58,000 of the counterfeit concoction.

At least 70 of Kong's associates in the multimillion dollar scam have also been arrested.

The arrests are part of Beijing's intense crackdown on counterfeit vaccines involving 20 cases.

Kong and his accomplices made more than $2 million by selling the saline solution mix as a vaccine in August last year. 600 of these fake vaccines were shipped to Hong Kong from where they were sent abroad.

Other criminals had inoculated people in rural areas through village doctors in their homes and cars.

The coronavirus pandemic that originated in Wuhan, is largely under control in China with strict lockdowns and efficient contact tracing measures