Published Tuesday, 24 April 2012
Television replays of the incident did not clearly show a foul. (© PA)
The 26-year-old found himself back in the spotlight over the weekend when he claimed his World Championship opponent had been dishonest during their first round match.
He accused Cao of "blatant cheating" - a "bit of a trait for Chinese players" - because he believes he did not own up to a push shot during the tenth frame.
Mark Allen, who went on to lose the match 10-6, issued a statement on Tuesday night in which he said sorry for offence caused to Cao and Chinese players as a whole.
"Following my recent comments in the press conference after my first-round defeat to Cao Yupeng, I would like to formally apologise to anyone who may have been offended," he said.
"Having taken some time to reflect on my comments I can appreciate that I overstepped the line at a time when I was heavily influenced by the emotions of a disappointing defeat.
"I would like to take this opportunity to apologise to Cao Yupeng if he felt that my comments were insinuating he were a cheat."
World Snooker boss Barry Hearn has already warned Allen that the controversial outburst will be dealt with very seriously.
"We have the powers to do anything providing we've acted reasonably," Mr Hearn said. "It's a fine, a potential suspension, or a ban."
Meanwhile the World Professional Billiards and Snooker Association (WPBSA) said it will be writing to Allen to initiate disciplinary proceedings.