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.