Anbang Insurance Group, one of China's most aggressive buyers of overseas assets, said on Wednesday its chairman was temporarily unable to fulfil his duties, just over a week after denying reports he had been barred from leaving the country.
The company gave few details but said he was no longer able to fulfil his duties for "personal reasons".
A Chinese magazine had reported that Mr Wu was detained by authorities last week, but later deleted its article.
Anbang is known for a number of high profile international acquisitions, like the purchase of New York's Waldorf Astoria in 2015.
The company, which manages some 1.65tn yuan (£190bn; $242bn) worth of assets, said in a statement that the chairman's duties would be managed by other senior executives.
It did not comment on the report by the independent Caijing magazine that he had been detained.
Earlier, Anbang had denied a report by the Financial Times that Mr Wu had been stopped from travelling abroad.
Best known overseas for its 2015 purchase of New York's landmark Waldorf Astoria hotel, Beijing-based Anbang has pursued a string of high-profile foreign acquisitions under Wu.
After a spate of successful deal-making worth over $30 billion, Anbang ran into recent roadblocks, failing to close on a handful of investments, and facing criticism over its opaque shareholding structure.