WPBSA (World Professional Billiards and Snooker Association) chairman Jason Ferguson said in a statement: “The WPBSA is responsible for the governance of snooker worldwide and takes very seriously comments made which could be perceived to be directed at a particular nation. The chairman of the disciplinary committee Nigel Mawer is making further inquiries into this incident. Mark Allen will be given 14 days to respond to the letter.”
Allen - the world number 11 from Northern Ireland - castigated China's world number 81 Cao for being guilty of a push shot in the 10th frame of a match he lost 10-6. Allen said referee Paul Collier failed to spot the push before proceeding to accuse two more Chinese players of cheating in the past.
"It was a big stage of the match considering I had put him under pressure last night to get back to 5-4. If the referee rightfully calls a foul there, I have a good chance of going 5-5. He (Cao) went on from there to pull away to 7-4," said Allen.
"It seems to be a bit of trait for the Chinese players. There's been a few instances in the past...fouls...and blatant cheating going on. It needs to be corrected because he (Cao) is a good enough player. He doesn't have to do that.
"He did look at the referee as soon as he done it as if to say: 'you're not going to call a foul here?' I looked at Paul and Michaela (Tabb) who was marking the match and Griffiths (former world champion and coach Terry) who was commentating on it. Anything that Terry says, I trust.
"He (Griffiths) pretty much confirmed it at the interval. It is a pretty sad state of snooker if it has to come down to that. Its not the first time. Maybe it is just a Chinese thing."
Allen was fined £1,000 for his criticism of the conditions at China's Haikou World Open last month before apologising. Ironically, Allen won the event.
Allen tweeted: "Dead cat found this morning. Any wonder this place stinks. Must be dead cats all round the town. This place is horrendous. It just baffles me how world snooker continuously go out of their way to put tournaments on in the middle of nowhere. Journey a nightmare. People are ignorant. Place stinks. Arena's rubbish, tables poor, food is horrendous. Other than that I love China."
Allen intimated earlier on Monday that he was no longer going to use the social networking medium of Twitter.