AstraZeneca, the Anglo-Swedish pharmaceutical giant, is facing a major crisis as its shares plummeted following reports of a widening fraud investigation in China. The company's stock fell by 8.4% on Tuesday, marking its worst day since March 2020. This dramatic drop came after reports surfaced that dozens of AstraZeneca's senior executives in China are implicated in a significant insurance fraud case.

The investigation, which has expanded to involve the public security bureau and other government bodies, centers around allegations that AstraZeneca's sales personnel manipulated patient test results to boost drug sales. This includes faking prescriptions for the lung cancer drug Tagrisso to exploit China's state medical insurance program.

AstraZeneca's China president, Leon Wang, is under investigation, and the company has stated it will cooperate fully with Chinese authorities. The probe has cast a shadow over AstraZeneca's operations in China, which is its second-largest market after the United States, accounting for 13% of its total revenue.

The fallout from the investigation has been severe, with AstraZeneca's market value dropping by £14.4 billion. The company, which has been operating in China for over 30 years, has faced previous challenges in the region, including a 2022 investigation into suspected medical insurance fraud by its employees.

Despite the negative news, analysts have mixed views on AstraZeneca's stock. While Deutsche Bank and UBS have maintained their Sell ratings, Goldman Sachs and Barclays have issued Buy ratings, citing potential growth opportunities.

AstraZeneca's commitment to the Chinese market remains strong, with plans to build a $450 million factory and several licensing deals with local firms. However, the ongoing investigation poses a significant risk to its future operations in the region.