Beijing has tightened its grip on a financial market plagued by irregularities and left reeling from turbulence. The latest effort involves the famous Chinese hedge fund manager Li Yifei, whose disappearance from public view in the past two days has prompted much speculation. Li is the chairwoman of the China unit of the Man Group, one of the world's largest hedge funds. Bloomberg on Monday quoted a source as saying Li had been taken into custody by police to assist a probe into market volatility and her mobile phone had been switched off. Read more: Nearly 200 people punished in China for 'spreading online rumours' including inflating Tianjin disaster death toll Li's husband, businessman Wang Chaoyong, denied the report. But he admitted his wife had been called to a special meeting with "relevant industry authorities" because of "the recent market volatility", mainland website Thepaper.cn reported. "Foreign funds need to give information [to the authorities]. Because of the sensitivity of the meeting, all the participants must turn off their mobile phones and are not to contact the outside [without permission]," he told the website. The same day, Wang told another mainland news outlet, Caixin, that Li was at "a meeting in London". In July, Beijing set up an investigation task force led by the Ministry of Public Security and financial regulators to crack down on illegal trading after a wave of panic sell-offs shocked domestic stock markets. Wang said his wife was not responsible for the market rout. Bloomberg's report stressed the questioning of Li did not imply any wrongdoing. A person familiar with the operation of foreign funds in China said it was most likely a fact-finding meeting for authorities to understand more about the operation of foreign hedge funds. "I don't believe the move is to target foreign funds. It is normal for the regulators to call up some fund managers to understand what they are doing. The US and Hong Kong regulators are not polite either when it comes to short-selling activities," he said. Rosanna Konarzewski, head of communications for Man Group, declined to comment. Li is considered one of China's most powerful businesswomen. Separately, Chinese financial journalist Wang Xiaolu and the stock market regulatory official Liu Shufan, implicated in a probe into suspected insider trading at Citic Securities, confessed on state television on Monday morning. Their appearance came hours after a midnight announcement that both men and four executives of the brokerage, including managing director XuGang, were being held. Xu and three others, including executive committee member Liu Wei, head of the company's securities financing business Fang Qingli, and company director Chen Rongjie, had been criminally detained for suspected insider trading, Xinhua reported. In mainland law, "criminal detention" precedes formal arrest. Wang Xiaolu, of Caijing , had been accused of fabricating and spreading false information.