No reliable source about this claim. All is from someone called from George Chen in Hongkong. Chinese government do not like guys like him who spread "unreliable" rumors like that.
Actually, it is not a news that Chinese authority is investigating anyone who is doing illegal trading like short sells but they still struggling to define what is illegal, so there are some many insider trading activities in China.
Quants in China no need to be panic. If quant hedge is illegal, they better just ban all computer use in the trading business.