SHIJIAZHUANG, Feb. 23 (Xinhua) -- Guo Zhouke, former president of the North China Pharmaceutical Co., Ltd, is under investigation, according to the Hebei provincial commission for discipline inspection on Thursday.

Guo is suspected of "serious disciplinary violations," said the commission in a statement.

North China Pharmaceutical Co., Ltd is one of China's biggest pharmaceutical companies.

Guo had also served as vice president of Jizhong Energy Group Co., Ltd.