Sanofi says it is taking "very seriously" allegations that some employees bribed more than 500 doctors in China six years ago.

The French drugmaker has moved centre-stage in the ongoing bribes scandal in China following allegations from a whistleblower who provided four documents to China’s 21st Century Business Herald newspaper. Those papers allege that Sanofi employees paid bribes to doctors in 79 hospitals totalling 1.71 million yuan (about $280,000) to prescribe the company's drugs.

Most of the payments were made to medical staff in hospitals in Beijing, Shanghai, Guangzhou and Hangzhou, and were listed as 'research expenses', the report claims. The newspaper alleges that Sanofi paid doctors 80 yuan every time a patient bought its products, with the largest payment being 11,200 yuan.

Sanofi has responded by saying it takes very seriously the allegations raised in the 21st Century Business Herald but adds that "at this time, it would be premature to comment on events that may have occurred in 2007". The Paris-headquartered firm said "we have zero tolerance to any unethical practice", saying that it has "established processes in place for reviewing and addressing such issues in a manner that is consistent with our legal and ethical obligations".

The allegations come after the bribery scandal that has engulfed GlaxoSmithKline in China this summer. Authorities in the country are also investigating a significant number of foreign and domestic pharmaceutical companies over pricing.