Sun Yuchen, who sparked a heated debate in Chinese social media after bidding a record $4.57 million to have lunch with Warren Buffett Photo: Courtesy of Sun Yuchen

Chinese blockchain entrepreneur Sun Yuchen, who canceled a charity lunch with US financier Warren Buffett on Tuesday morning, denied media reports that he was involved in illegal fundraising and money laundering.

Sun said on his Weibo account that reports concerning his illegal fundraising and money-laundering are untrue. He affirmed that his business, TRON, has complied with Chinese laws and regulations. 

Sun's cancellation of the lunch with Buffett sparked heated discussion online, as most netizens questioned whether Sun had used this excuse for personal hype and marketing of his business. 

Sun said on his Weibo account on Tuesday that his meeting with Buffett was canceled due to a sudden attack of kidney stones that he suffered. 

"[I am] receiving treatment in a hospital and am in stable condition (now) and recovering," said Sun, who declined any media interviews. He said that he would make a statement to the public after he was released from the hospital.

The annual luncheon auction with financier Buffett raises money for the San Francisco-based charity Glide Foundation. 

Sun said on his Weibo account that his donation to Glide was completed. 

In early June, Sun won an annual charity auction to have lunch with Buffett via a $4.6 million bid — a record high. The highly anticipated meeting was scheduled to take place in San Francisco on Thursday.

Sun, the 28-year-old founder of blockchain platform TRON, "fell ill with kidney stones," the Tron Foundation said on its Twitter account on  Tuesday morning, noting that "relevant parties agreed to reschedule at a later date."

Some Chinese netizens expressed concern for Sun and said that nothing is more vital than personal health.  "Kidney stones may affect appetite," a netizen named TheFleaLife said on Weibo.

But many raised doubts, questioning whether the excuse was just a new form of hype from Sun, who is known to be good at marketing. "Sun has successfully created big news ... the first man to break an appointment with Buffett," a netizen named Tusdt said on Weibo.

"What a coincidence! It is like an excuse to play truant," a netizen named FakeLondon said.

According to an online survey conducted by National Business Daily on Weibo, as of press time, about 12,500 netizens were eager to know the follow-up to the canceled lunch with Buffett. More than 3,700 asked if Buffett would visit Sun and 8,600 netizens wanted to know how to deal with the party who canceled an appointment.

As a controversial figure, Sun convinced Buffett to move the charity lunch from its traditional New York location to Silicon Valley, according to media reports. In an interview with the Global Times in June, Sun said that he would update Buffett on technological progress in the blockchain world and clear up some "misunderstandings" Buffett has about the technology during the lunch.