By Li Hongmei

A US citizen held in Shanghai amid an investigation into China's pharmaceutical industry is the wife and business partner of a detained British consultant, sources said yesterday.

Yu Yingzeng, general manager at the ChinaWhys business risk advisory firm, and her husband, Peter Humphrey, the company's managing director, were detained by Chinese authorities in Shanghai on July 10, the sources said.

It is unclear if the detention of the couple is directly related to a police investigation into bribery allegations against British drugmaker GlaxoSmithKline.

ChinaWhys has done work with drugs companies, including GSK, other sources have said. It was not clear if either Yu or Humphrey had any legal representation.

GSK has been accused by China of funneling up to 3 billion yuan (US$489 million) to travel agencies to facilitate bribes to doctors and officials. GSK has said some of its senior Chinese executives appear to have broken the law.

Yu is a founder at ChinaWhys, which offers "discreet risk mitigation solutions, internal process audits, due diligence and commercial investigation services," its website says.

Humphrey, also a founder of ChinaWhys, worked as a journalist for Reuters in the 1980s and 90s.