Switzerland pharmaceutical giant Novartis announced this week that it is conducting an internal investigation amid allegations that its eye care unit Alcon made improper payments to doctors in China.

The 21st Century Business Herald, a state-owned newspaper based in Guangzhou, published a report this week detailing a whistleblower's account that Alcon paid bribes to doctors in more than 200 Chinese hospitals in order to push its sales of lens implants, passing off the payments as “research fees,” according to published reports.

The latest probe marks the second time that Novartis has come under scrutiny for allegations of bribery. In August, the 21st Century Business Herald detailed another whistleblower's account that Novartis bribed doctors to boost drug sales.

The Swiss drug maker is not the only one to come under the spotlight for bribery allegations. In recent weeks, Chinese authorities have investigated Eli Lilly; French drug maker Sanofi; Denmark's Novo Nordisk; Belgium's UCB; and British company GlaxoSmithKline.