SHANGHAI (REUTERS) - Chinese cryptocurrency entrepreneur Justin Sun issued a lengthy public apology on Thursday (July 25) for the manner in which he promoted his US$4.57 million (S$6.25 million) charity lunch with Mr Warren Buffett, raising questions over whether the event will go ahead.

The 29-year-old was scheduled to dine with the American billionaire investor on Thursday in San Francisco after winning an annual auction. He said he hoped the meal would "bridge the gap between institutional and traditional investors and the realm of cryptocurrency and blockchain technology".

He aggressively promoted the lunch on social media only to postpone it earlier this week, saying he had fallen ill with kidney stones.

Such high-profile events are unusual in China's cryptocurrency industry, which has been under heavy regulatory scrutiny for the past two years. The authorities have warned about speculation risk and banned initial coin offerings, prompting many industry players to keep a low profile.

Amid the publicity surrounding the event, reports in Chinese media suggested that Mr Sun's businesses were involved in illegal activities and that he had been barred from foreign travel. Mr Sun denied all allegations.

In Mr Sun's Thursday statement posted on his Weibo microblog account, he said he had been immature and "over-marketed" himself, and that his original good intentions to arrange the lunch with Mr Buffett had resulted in unexpected consequences that led him to neglect his social and public responsibilities.

"This has resulted in a bad influence on the public, and incited the worries of the regulatory bodies which care for me," he said.

He did not specify what prompted the apology, nor did he state when or whether the lunch will be rescheduled.

Mr Sun's company, the Tron Foundation, did not respond to a Reuters request for comment. US investment firm Berkshire Hathaway, which Mr Buffett chairs, did not respond to a request for comment outside regular business hours.

Mr Buffett offered the lunch by auction to raise money for anti-poverty charity Glide, which has said it has received Mr Sun's donation.

Mr Sun said he would actively cooperate with regulatory agencies to discuss his businesses' structure and plans, and that he places great importance on financial stability and curbing risk.