The Shilin District Prosecutor's Office launched an insider trading investigation after shares of Taiwan vaccine maker Medigen Vaccine Biologics Corporation​ (MVC) soared ahead of the announcement of positive results from its clinical trial II.

An insider trading investigation into a Taiwanese manufacturer of Covid-19 vaccine has sparked broader concerns about financial regulation in Taiwan, with Tsai Ing-wen's government implicated.

Taipei-based Taiwan's Shilin District Prosecutor's Office told the Financial Times that it is investigating Medigen Vaccine Biologics Corporation. The company's shares soared more than 20 percent in June, days before announcing positive results from a phase II clinical trial of the vaccine. Prosecutors declined to give further details of the investigation.