Pharmaceutical giant GlaxoSmithKline announced last week that it is under investigation by Chinese police amid allegations that it made improper payments to doctors in China.

GSK says it is being probed over allegations that senior management at GSK's China operations made bribery payments in the form of cash payments, lavish dinners, and all-expenses-paid trips to doctors in China in exchange for prescribing Botox, according to internal documents and e-mails obtained by the Wall Street Journal.

GSK's board of directors and compliance officers were made aware of the alleged improper payments by an anonymous whistleblower, the WSJ reported.

 “After a thorough investigation, we found no evidence to support these allegations. Nevertheless, we are investigating these new claims,” a GSK spokesman told the WSJ. “However, our inquiries to date have found no evidence of bribery or corruption in relation to our sales and marketing of therapeutic Botox in China.”

The news of the latest probe comes one year after the company reached a record $3 billion False Claims Act settlement with the Justice Department—the largest healthcare fraud payout in U.S. history. The case stemmed from a lawsuit filed in January 2003 by two whistleblowers, former GSK sales representatives Greg Thorpe and Blair Hamrick, who accused the company of off-label, unapproved marketing and promotion of several of its blockbuster drugs, including Paxil and Wellbutrin. The complaint also alleged that GSK failed to report certain safety data.