The alleged molestation of a 9-year-old girl by a Shanghai real estate tycoon has caused stock prices plunge of three companies controlled by the man.

The tycoon, Wang Zhenhua, 57, is now detained by Shanghai police, facing criminal charges of child molestation. On Wednesday, his son Wang Xiaosong has been made as the new chairman of Seazen Holdings.

Shares of Shanghai-based real estate developer Seazen Holdings fell by 10 percent on Thursday, the daily price decline floor set by China's A-share markets.

Two other firms listed at the Hong Kong stock market, controlled by Seazen Holdings, Future Land Development Holdings and S-Enjoy Service Group kept falling over 10 percent on Thursday, after plunging more than 20 percent on Thursday.