BEIJING — Missing Chinese investment banker Bao Fan is cooperating with a government investigation, his firm China Renaissance said in a filing Sunday.

The company’s Hong Kong-listed shares have plunged 29% since the firm said on Feb. 16 it was unable to reach Bao. He is China Renaissance’s controlling shareholder, chief executive officer and founder, among other roles.

“The Board has become aware that Mr. Bao is currently cooperating in an investigation being carried out by certain authorities in the People’s Republic of China,” China Renaissance said in a filing with the Hong Kong stock exchange Sunday.

In both filings this month, China Renaissance said its business continued to operate normally.

Its shares hit a record low of 5 Hong Kong dollars (64 cents) on Feb. 17 but have since recovered slightly.

Earlier this month, Chinese financial news outlet Caixin pointed out that Bao’s disappearance followed the investigation of another China Renaissance executive, Cong Lin.

Cong was also the chairman of the firm’s subsidiary Huajing Securities.

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 filings about Bao did not mention that probe, and a representative did not share additional information when contacted.