Sun Yuchen, or Justin Sun, the 29-year-old cryptocurrency entrepreneur and this year's Warren Buffett lunch winner, apologized for his excessive marketing and publicity stunt on the Chinese social media platform Weibo on Thursday.

Sun said the lunch meeting came from his admiration of Warren Buffett and his love for philanthropy, and he also wanted to take the opportunity to promote the blockchain industry, though it turned out to be an overblown marketing attempt.

The Chinese entrepreneur won the auction for this year's Buffett lunch with a record high $4.57 million bid in June, while he canceled the planned lunch meeting, claiming he had "a sudden kidney stone attack" in a Tuesday post on Weibo.

However, according to a Wednesday report from Chinese media outlet Caixin, Sun was put on a border control list by Chinese authorities that would restrict him from traveling abroad for allegations including illegal fundraising, money laundering, gambling and spreading pornography.

Sun said in a letter of apology that he had the "profound respect and humility" to communicate with Caixin, and would like to have a "transparent, unreserved conversation" with Caixin to talk about the business of his company and industry development.

He also expressed his apologies to Sogou CEO Wang Xiaochuan, who Sun once derided as a "wage earner" while calling himself an "entrepreneur" during an interview with the Chinese news website Jiemian.

Specifically, Sun said he will introduce his business and industry development to and cooperate with regulatory agencies, meet their requirements and maintain on-time responses and long-term communication.