Police have visited the Shanghai office of British drugmaker AstraZeneca, as China intensified a crackdown on commercial corruption in the medical sector.

Amid a criminal investigation into another British pharmaceutical giant, GlaxoSmithKline, officers from Shanghai's Public Security Bureau are said to have detained a sales employee of AstraZeneca after visiting its sales office in Shanghai on Friday.

"We believe that this investigation relates to an individual case, and while we have not yet received an update from the public security bureau, we have no reason to believe it is related to any other investigations," a spokesman for the pharmaceutical company told The Telegraph on Monday, adding that the company "does not tolerate any illegal or unethical conduct in our business activities".