China has started investigating French drugmaker Sanofi for allegedly bribing more than 500 Chinese doctors with about 1.7 million yuan ($277,600) of payments to raise sales, China's Xinhua state news agency reported.

Xinhua cited a health bureau official as saying the team investigating Sanofi would include disciplinary authorities and the Beijing municipal health bureau, and it would look for clinical research programs with lists of patient names and medical reports.

Sanofi said this week it took "very seriously" allegations published in a Chinese newspaper that its staff bribed more than 500 doctors in China in 2007 to raise sales.

An anonymous whistleblower told the 21st Century Business Herald newspaper that Sanofi staff paid bribes totalling about 1.7 million yuan to 503 doctors at 79 hospitals in Shanghai, Beijing, Hangzhou and Guangzhou in late 2007.

Sanofi said in a statement it was aware of the report but it said it was premature to comment on events that may have occurred in 2007. It said it had zero tolerance for any unethical practices.

Chinese investigations into bribery and over-pricing have centred on Britain's GlaxoSmithKline Plc (GSK) but the latest developments suggest they could have a wider impact across the pharmaceuticals industry.

Other companies including Danish drugmaker Novo Nordisk, AstraZeneca, Eli Lilly & Co and Belgium's UCB SA have all reported visits from authorities to their China offices.

Analysts have said the investigations into pharmaceuticals are likely to precede a push by authorities for stricter price controls, which could cut annual growth in drug sales in China by as much as half to 10 percent.