An ex-Pfizer compliance officer is suing his former employer claiming wrongful termination and whistleblower retaliation after discovering the company allegedly paid $168 million to potentially influential government officials (PIGOs) in China.

Frank Han, a former director of global compliance analytics for the pharmaceuticals giant, originally filed his lawsuit in California state court before it was moved to federal court earlier this month.

From April 2019 through September 2021, Pfizer allegedly paid 10 times the amount of money on PIGOs in China than they spent elsewhere during the same time frame, the lawsuit alleged. Out of the $168 million, $138 million went to corporate sponsorships, the lawsuit stated. Han said he uncovered the data from a fraud detection algorithm he developed to analyze the company’s global external funding.

In a November 2021 virtual meeting, Han raised compliance concerns and potential Foreign Corrupt Practices Act violations to his immediate supervisor and other colleagues, per the lawsuit.

In Han’s next performance review, he received a reduced score and was told his work was not translating into “end products” by his direct supervisor, the lawsuit alleged. In his previous performance review, he received a higher than perfect score, the lawsuit noted.

Han’s direct supervisor later screamed at him, accused him of project delays, and told him to quit, the lawsuit alleged. After later being denied a request to report to a different supervisor, he allegedly received a further downgraded performance review.

In August 2022, Han filed a performance review rebuttal and his compliance concerns to Pfizer’s ombudsman adviser. She referred him to the compliance division chain of command and open-door policy. A month later, the lawsuit said Pfizer broke Han’s rebuttal into three categories—retaliation issues, performance review issues, and business issues—and opened investigations into all three.

Following the business issues probe, the company said, “‘Per corporate audit’s investigative process, no further action has been deemed necessary,’” the lawsuit stated.

Pfizer never informed Han of the results of its other two investigations, the lawsuit alleged. In October 2022, he told Pfizer he would be reporting his concerns to the Securities and Exchange Commission (SEC) because of a lack of transparency regarding Pfizer’s probes, the lawsuit said. A month later, Pfizer terminated him.

Han’s whistleblower attorney, Stuart Meissner, confirmed the SEC interviewed Han after responding to his tip and continues to investigate the submission.

The lawsuit lists lost wages, mental and emotional distress, legal fees, injunctive and declaratory relief, and interest, among other damages it will demand, according to its proof at trial, Han’s California lawsuit attorney Zulma Munoz said.

Pfizer did not respond to a request for comment.