Police chief who put away Zhou Yongkang to head probe of China's securities industry - Bloomberg
Fu Zhenghua, now a deputy minister for public security, previously supervised the case against former Politburo Standing Committee member Zhou Yongkang, three people familiar with the matter told Bloomberg.
The Ministry of Public Security did not immediately respond to a request for comment.
Haitong Securities, Guosen Securities and CITIC Securities have been subject to probes by the China Securities Regulatory Commission (CSRC) for suspected violations of margin trading rules.
After China's stock market slump in mid-June, Beijing began cracking down on insider trading and short-selling, which it said were partly to blame for market volatility.
(Reporting by Engen Tham; Editing by Ryan Woo)