Outside China, some of the deals led regulators to ask questions about the tycoons behind them. Some wealthy people in China list their holdings under the names of relatives or associates to avoid scrutiny, a practice that has attracted criticism inside and outside the country.

In the case of Mr. Li, the mines that he told A.C. Milan he controlled have been owned by four different people since last year, according to Chinese corporate records. The business changed hands twice for no money, the documents show.

Mr. Li declined an interview request through A.C. Milan. The club spokesman defended Mr. Li on his business disputes, saying that sometimes he was a victim and that sometimes he was not aware of complicated rules. The spokesman also said the club was evaluating several refinancing proposals and was confident it could cover the loan.

Chinese spending on soccer totaled $1.8 billion over the past five years, according to Dealogic, a data provider, but Chinese officials are putting a stop to the spree amid concerns about the flight of money abroad.

“There’s a lot of ways to invest in football and the sports industry for much less money,” said Mark Dreyer, who tracks Chinese soccer investments on his website, China Sports Insider. “People were basically using the government’s previous push for sports as a way to diversify into different industries and get their money out of China.”

Mr. Li had plenty of reasons to buy A.C. Milan. President Xi Jinping had professed his love for soccer and wanted China to be a superpower in the sport by 2050. The Chinese government had laid out a plan for increasing sports investment.

An acquisition of A.C. Milan would be a marquee deal. A decade ago, the club was home to some of soccer’s biggest talents, including Ricardo Izecson dos Santos Leite, who is known as Kaká, and Andrea Pirlo. It was a seven-time European champion.