Medical experts in China have urged people not to take any urgent action, following claims that Swiss pharmaceutical giant Roche had failed to disclose reports that people had died while taking some of its cancer drugs.

Officials in China said there is no evidence so far of any direct link between the problems and the drugs.

It has been reported that all of the reactions took place in the United States over the past 15 years, with medicines used to treat breast cancer, bowel cancer, hepatitis B, and skin and eye conditions.