Guo Guangchang, Fosun Chairman, Assisting with Investigation

A Fosun spokeswoman declined to give any details about the meeting.

Mandarin Capital Partners founder Alberto Forchielli, who has 20 years of business experience in China, said: “Should Guo, well known overseas, be found to be at the centre of a graft investigation, this would be a strong signal to the world that China is serious about its anti-corruption campaign.”.

On Friday, Chinese news agency Caixin reported the closely held company had been unable to reach Guo since midday on December 10.

Last month the head of Guotai Junan International, the Hong Kong branch of a major Chinese brokerage, also disappeared without explanation.

Zhang said that in a series of deals in Shanghai, Fosun has bought stakes of less than 50 percent in state-owned companies but gained management control.

“A lot of companies will be on the investigation list and it will alert all the investors”, he said.

On Monday, the shares of Fosun companies experienced drops of between 5 and 12 percent.

Shares in Fosun International plunged Monday after it announced that the parent company’s chairman, Guo Guangchang – regarded as “China’s Warren Buffet” – was cooperating with Chinese investigators.

Fosun Group is one of China’s biggest private companies, and has interests in property, finance, pharmaceuticals, steel and entertainment, and has been aggressively buying assets in Europe and North America, including Club Med.

Mr Guo’s disappearance comes in the midst of a sweeping anti-corruption crackdown led by President Xi Jinping in which dozens of executives at state-owned companies have been detained or questioned. Bankers also said Fosun’s high debt levels could become a concern if access to funding is diminished.

Instead he discussed Fosun’s strategy and performance, receiving a standing ovation from the people gathered at a Shanghai hotel for the meeting, Reuters reported, citing sources who attended the meeting.

It remains unclear what the investigation covers and whether or when it will end, enabling Guo to resume his full duties.

Guo, 48, is China’s 11th richest person, according to Forbes China Rich List 2015, with personal assets of $6.9 billion.

Shares of Fosun International and its controlled companies were suspended in Hong Kong and mainland on Friday after it was confirmed Guo as helping a judiciary investigation.