(Yicai Global) July 31 -- Serum Bio-Technology’s shares plunged after Chinese authorities began investigating the chairman of the antiserum and antitoxin products maker on suspicion of public duty-related crimes amid a crackdown on corruption in the pharmaceutical industry.

After tumbling by as much as 16.5 percent at today’s market open, Serum [SHA: 688163] ended 11.5 percent lower at CNY19.18 (USD2.68) a share in Shanghai.

The family of Fan Zhihe received notice of his detention and the case filing by the Shanghai Supervision Commission on July 29, Shanghai-based Serum announced yesterday.

Fan may be suspected of bribery, encouraging bribery, or joint duty crimes, Yang Cheng, a lawyer at Beijing Long An Law Firm in Shenzhen, told Yicai Global.

China’s National Health Commission kicked off a 12-month crackdown on corruption in the pharmaceutical industry this month and the National Supervisory Commission of the Central Commission for Discipline Inspection also directed it officials to support the clampdown.

Previously, Zhou Wei, de facto controller and chairman of medical software developer Winning Health Technology Group, was put under investigation by authorities in Maoming, Guangdong province on July 1 for alleged bribery.

Serum, which went public on Shanghai's Nasdaq-like Star Market on March 11 last year, is one of China’s few antiserum and antitoxin manufacturers. Revenue from its antivenom business was CNY140 million (USD19.6 million) in 2022, accounting for about 80 percent of its total income.

Fan, his wife Zhao Aixian, and their son Fan Tiejiong are persons acting in concert and jointly hold a 56 percent stake in Serum, according to its 2022 annual earnings report.

Editor: Martin Kadiev