AstraZeneca says staff detained in China amid reports of a drug-import investigation

Some employees of British pharmaceutical giant AstraZeneca have been detained by police in China as part of an investigation, the company confirmed Thursday.

"We are aware a small number of our employees in China are under investigation and we have no further information to share at this point," an AstraZeneca spokesperson told CNBC by email, without disclosing details on what the investigation concerns.

The confirmation came in response to reports earlier Thursday from Bloomberg News, which said that there were five current and former employees being probed who are all Chinese citizens who worked within the company's oncology division.

One probe is related to the company's collection of patient data, and the possibility that it infringed China's data-privacy laws and the other concerns some of the individuals' role in importing a liver cancer drug that has not been approved for distribution within mainland China, Bloomberg reported, citing people familiar with the matter.

Shares of AstraZeneca fell as much as 6.8% in early deals before paring losses. They were last seen down 2.2% by 12:18 p.m. London time.

The investigation is reportedly being conducted by police in the southern Chinese city of Shenzhen. A spokesperson for the Shenzhen police force was not immediately contactable by CNBC.

The British drugmaker, which produced one of the leading Covid-19 vaccines, has a strong presence in China and has often talked up the growth opportunities of the market.