The billionaire chairman of Fosun Group, Mr Guo Guangchang, attended an annual meeting in Shanghai yesterday after having gone missing since last Thursday.
His disappearance had sparked talk that it was in connection with an official graft probe amid fears that the private sector is increasingly the target of a corruption crackdown.
Yesterday, Mr Guo did not mention the probe and discussed only company matters, media reports said, quoting sources.
Fosun, which owns the Club Med chain of resorts and has a stake in Canada's Cirque du Soleil, said on Sunday that Mr Guo is assisting with an investigation mostly concerning his "personal affairs".
Without elaborating further, a Bloomberg report yesterday said the probe has to do with former Shanghai vice-mayor Ai Baojun, who was reported to be under investigation for corruption last month.
But the probe that ensnared one of China's best-known private entrepreneurs has added to jitters in the country's financial and business sectors. President Xi Jinping's anti-graft drive has nabbed a number of powerful officials but very few from the private sector.
While details of the latest probe are scant, it comes on the back of a string of anti-graft investigations into the financial industry after a stock market rout earlier this year wiped trillions of yuan off global markets. Since August, many executives have been arrested or detained, while others have gone missing.
Ping An Securities' former chief Xue Rongnian was arrested on suspicion of insider trading on Nov 20, Caixin magazine reported last Friday. Last month, Mr Yim Fung, the chairman of Guotai Junan International, the Hong Kong unit of one of China's biggest brokerage firms, also disappeared.
University of Nottingham's China politics expert Steve Tsang said that under China's "consultative Leninist" system, business tycoons are not loved per se but are used by the Communist Party to achieve its goals, the most important of which is the continuation of its power.
"Tycoons are not themselves anti-corruption targets. But they can become targets for government action if they are acting against the party's core interests, such as destabilising a vital part of the economy like the Shanghai market," he told The Straits Times.
The crash might have shown that some of these tycoons were profiteering at the expense of the party and that is why Mr Xi could be taking action against them, Professor Tsang said, adding that it remains unclear if Mr Guo played a significant role in the rout.
Ms Anne Stevenson-Yang, co-founder of J Capital Research in Beijing, said, however, that the financial and business sectors have long been in the cross hairs and the stock market crash was a good excuse for the government to pursue corruption in the industry.
But Shenzhen University analyst Ma Jingren told The Straits Timesthe recent spate of investigations should not be seen as specifically targeting these sectors or private industry. "With mergers and acquisitions in the corporate sphere, it's an area where large opportunities for corruption exist. It's only natural that the anti-graft campaign will implicate business people too.
"Government agencies and businesses should be held to the same clean governance standards."
But should a high-profile figure like Mr Guo be implicated in a probe, it is likely to send shock waves through the private sector, analysts say, and could spark a capital flight.