HONG KONG (Reuters) - Shares of boutique investment bank China Renaissance ( CSCHF ) fell as much as 72% to a record low on Monday when they resumed trading 17 months after being suspended during a probe involving its then-chairman and CEO Bao Fan.

Trading was suspended on April 3, 2023, due to a delay in publishing its 2022 results after mainland Chinese authorities requested Bao's cooperation in an investigation.

The star dealmaker, who founded China Renaissance ( CSCHF ) in 2005, has not been seen publicly since before the suspension. A Chinese financial publication reported in May last year he was detained by disciplinary and supervision officials. Authorities have so far not provided any explanation for his absence.

Bao is one of several high-profile executives in China's finance industry who have gone missing in recent years with little explanation amid a sweeping anti-corruption campaign led by President Xi Jinping.

China Renaissance ( CSCHF ), which appointed Xie Yi Jing to replace Bao as chairman and CEO this year, published its long overdue earnings results last week, allowing it to resume trading.

The investment bank posted last week an attributable loss of 471.9 million yuan ($66.55 million) for 2023, and a loss of 73.8 million yuan for the six months ended June 30.