In a hospital on the outskirts of Beijing, the hallway outside the main nurses’ station was unusually empty yesterday. “We usually have four or five representatives from the pharmaceutical companies who hang around here, but today they’re all gone,” said one mid-level hospital executive. “They wait out there and try to invite doctors for meals and massages.”

These sales representatives, all of whom work for Chinese pharmaceutical companies, are just the most obvious manifestation of an endemic culture of bribery and kickbacks that pervades China’s health sector, according to doctors, investors and senior medical officials.

A widening Chinese investigation into bribery and corruption in the pharmaceutical industry has so far led to the detention of more than a dozen employees of GlaxoSmithKline in China, and is expected to affect other companies as well. Sir Andrew Witty, GSK chief executive, has warned investors of the potential impact of the investigation, which is focusing on deals totalling Rmb3bn ($488m). So far, no Chinese companies have been named in the industry-wide investigation, although the practice of bribing doctors, hospital administrators and health officials is rampant.