Leon Wang, executive vice president in charge of China and the broader Asian region, is being detained while the Chinese government is probing AstraZeneca employees, the drugmaker says.

Two current and two former senior AstraZeneca Plc executives in the group’s China unit are under investigation in a probe into alleged breaches of laws around drug importation and data privacy, the company said.

China's investigation of AstraZeneca's top executive in the country is raising questions about the company's tactics there.

Chinese authorities detained the head of AstraZeneca’s China business last week, a move that threatens to dim foreign business confidence in the country further. The detention follows an investigation into the alleged illegal importation and sale of a cancer drug,

AstraZeneca Plc shares plunged in London, erasing about £14 billion ($18 billion) of market value, amid escalating concerns over a Chinese probe into the UK drugmaker.

Pharmaceutical giant AstraZeneca said Thursday that the head of its China operations had been detained, after reports the firm was under investigation for potentially illegal data collection and drug imports.