Shares of the company that operates one of China’s top investment banks, China Renaissance, plunged on Friday after the firm said it had lost touch with its founder Bao Fan, one of the country’s most high-profile bankers and a top tech-sector dealmaker.

China Renaissance Holdings said in a filing to Hong Kong’s stock exchange on Thursday that it had been unable to contact Bao, who has worked on major deals including e-commerce company JD.com’s $2 billion initial public offering and the public listing of short video platform Kuaishou in Hong Kong.

The company said that it was “not aware of any information that indicates Bao’s unavailability” was related to the business of the group.

Bao’s disappearance follows a crackdown on big technology companies in the past two years that officials in China said had been wrapped up.

Shares in China Renaissance fell as much as 50 per cent Friday in Hong Kong. They were down about 28 per cent in the afternoon.

China Renaissance did not immediately respond to emailed requests for comment on Friday.

Bao’s disappearance comes months after former China Renaissance president Cong Lin was taken away by Chinese authorities in September last year.