BEIJING — Prominent Chinese investment banker Bao Fan is missing, his company China Renaissance Holdings said late Thursday.

China Renaissance said it "has been unable to contact Mr. Bao Fan," according to a filing with the Hong Kong stock exchange.

The Beijing-based fund manager and investment bank is operating normally, the filing said.

Bao is the firm's controlling shareholder, as well as chairman, executive director and CEO. He did not immediately respond when contacted by CNBC about the news.

Shares of China Renaissance plunged by more than 20% in Hong Kong trading Friday.

Alibaba-affiliate Ant Group was one of three major investors in China Renaissance leading up to its own listing in Hong Kong in 2018. In late 2020, Chinese authorities abruptly suspended Ant's plans for a massive initial public offering.

China Renaissance has played an important role in China's internet tech world in the past decade. The investment bank advised Meituan and Dianping in their massive merger, and subsequent IPO in Hong Kong.

China Renaissance was also advisor to the merger that became Didi, and was an underwriter of the ride-hailing giant's U.S. IPO in June 2021.

Chinese authorities began to tighten their scrutiny on overseas listings that summer.

Days after Didi's IPO, authorities announced a cybersecurity review into the company, halting new user registrations. The company delisted later that year. Didi said last month it received approval to register new users again.

Despite greater caution on China investing after Didi's IPO, China Renaissance's Huaxing Growth Capital announced in October 2021 it received nearly $550 million in a fund closing.

Chinese Financial News outlet Caixin pointed out that Bao's disappearance followed the investigation of Cong Lin.

Cong was the chairman of China Renaissance's subsidiary Huajing Securities until earlier this month, according to business records database Tianyancha.

The China Securities Regulatory Commission Shanghai bureau said in September that Huajing violated securities law requirements regarding corporate governance, and asked Cong to comply with an investigation.

China Renaissance's filing about Bao Fan did not mention the probe, and a representative did not share additional information when contacted.

The company's official WeChat account includes announcements dated this week and last month with quotes from Bao. A post from early December shows Bao attending a recent event in Beijing.