Chinese tycoon Guo Guangchang, who was detained by police last week, has made an appearance at Fosun’s annual meeting in Shanghai.

The Fosun International chairman was first reported missing on December 11. The company later revealed he was assisting authorities with a probe.

Fosun president Wang Qunbin said the investigation mostly concerned Guo Guangchang’s personal affairs, not company business.

Wang Qunbin said he could not give more details as the investigation was “sensitive”.

On December 14, the website Caixin reported that Guo Guangchang, one of China’s richest men, had been released by police.

The businessman received a standing ovation at company meeting, a person in the audience told Reuters.

A string of senior executives at Chinese companies have temporarily gone missing this year amid a crackdown by Beijing on its financial sector.

Citic Securities, China’s biggest brokerage, said earlier this month it was unable to contact two of its top executives following reports they had been asked by authorities to assist in an investigation.

Guo Guangchang, 48, has been described as “China’s Warren Buffett”. Fosun Group has interests spanning media, insurance, real estate and retail.

It recently took control of French holiday group Club Med in a deal worth some $1 billion.

Fosun International, the parent company of Shanghai-based Fosun Group, was listed on the Hong Kong stock exchange in 2007.

Its shares were suspended on December 11 and fell more than 10% when trading resumed on December 14.

Shares in Fosun Pharmaceutical, which is also listed in Hong Kong, dropped a similar amount.

Guo Guangchang’s sudden absence, and the lack of detailed information released by the company, underlines the opaqueness of China’s legal system, analysts say.