China's most famous businessman has not made any public statement in two months, prompting speculation about his whereabouts.
Jack Ma, the 56-year-old founder and executive chairman of Alibaba Group, put out his last tweet on October 10.
That was to announce a partnership with the Duke of Cambridge and other global leaders on the Earthshot Prize.
That same month, Ma complained at a business conference how Chinese regulators were stifling innovation in the financial-services sector.
In November, government officials suspended his initial public offering of the Ant Group on the Hong Kong and Shanghai stock exchanges.
This reportedly came on the orders of Chinese president Xi Jinping, according to the Wall Street Journal.
Alibaba Group owned a one-third stake in the Ant Group, of which Ma was the controller. The news drove down Alibaba shares by seven percent.
Ma did not appear on his own show, Africa's Business Heroes, for its final episode. According to CNBC, the program even scrubbed his photo from the event's website.
Forbes magazine estimates Ma's net worth to be US$58.4 billion, making him one of the world's richest men.
The Alibaba Group is an ecommerce giant that also owns Hong Kong's most influential English-language newspaper, the South China Morning Post.
Last April, the company announced a $40-billion investment in cloud computing to try to seize market share from U.S. tech giants Microsoft, Google, and Amazon.More