Watch O'Sullivan's emotional news conference

An emotional Ronnie O'Sullivan has attacked snooker authorities for using "threatening" language and said he will not be "bullied" by them.

The five-time world champion is angry at a disciplinary letter sent to him.

After beating Gary Wilson in the first round of the World Championship, O'Sullivan said: "I phoned [World Snooker chairman] Barry Hearn four weeks ago and told him I am done with you and your board.

"I don't think I've done a lot wrong."

"A friend told me to let the lawyers deal with it. I won't get involved anymore because I am not being bullied."

Why is O'Sullivan upset?

Since victory at the Masters in January, five-time world champion O'Sullivan has only replied to questions by the media with one or two-word answers, and has also sung an Oasis song in reply, and on another occasion responded as a 'robot' in protest at his perceived mistreatment by the sport's authorities.

quote If I did not have good lawyers, I would probably have walked away because I am too old to be dealing with things like that Ronnie O'Sullivan

That grievance seemingly dates to an incident during his record-breaking seventh Masters triumph at Alexandra Palace, when he publicly criticised a referee and swore at a photographer.

World Snooker, the commercial arm of the sport, referred O'Sullivan's comments to governing body the WPBSA, which ultimately took no action as it accepted his explanation of the incidents.

However, O'Sullivan was sent a letter by the WPBSA about his behaviour and warned he could face further sanctions including a fine. He responded by saying that repeated disciplinary action could cause him to reduce his playing time and media commitments, among other things.

In five events since then, O'Sullivan has failed to win consecutive matches.

Explaining his behaviour, the Englishman said: "I have no problems with the press. Sometimes I say things I should not say, I get myself into hot bother, and I get a letter through saying I need to respond in 14 days - a day before a tournament.

"It messed up my last three or four tournaments. I did not really win a match and it is not fair on the fans or those who invested in me.

"I phoned Barry Hearn four weeks ago and told him I am done with you and your board of people. A friend of mine told me to let the lawyers deal with it. I won't get involved anymore because I am not being bullied. I am not letting people do that to me ever again.

"I just want to play and have fun. I like Barry but I am not being intimidated or bullied anymore. The language can be quite threatening and intimidating in some of these letters. It is very unsettling.

"To go in with all that on my head, having to see lawyers and having to fight off something I feel I should not have to, they pushed me too far.

"If I did not have good lawyers, I would probably have walked away because I am too old to be dealing with things like that."

World Snooker said it was unwilling to comment.

'This felt different' - analysis

BBC Radio 5 live's George Riley at the Crucible Theatre:

"We had no idea whether Ronnie would show up and, when he did, he was visibly emotional. Given he has chosen not to engage with the media since the Masters other than through robot impressions and Oasis songs, I didn't feel there was any alternative but to challenge him.

I have heard Ronnie threaten to retire and talk of falling out of love with the game on so many occasions that you no longer bat an eyelid when he does so. But this felt different - his voice was cracking with emotion when he spoke of feeling bullied, intimidated and threatened by the governing body and its leader Barry Hearn. There were nerves among the press too. It felt like a very tense 10 minutes.

Whether you side with O'Sullivan on this or feel - like Hearn does - that his behaviour is becoming embarrassing, there was raw anger here at the guys who run this sport. While some fellow players feel O'Sullivan receives preferential treatment, he himself feels persecuted.

This was a powerful and reasoned explanation as to why he is so upset. If this had come sooner rather than a series of childish media conferences, O'Sullivan might have found far more sympathy. Yet it appears that in his war with World Snooker, his relationship with the media has become a casualty."

'Another world title won't make a difference'

O'Sullivan, though, did not speak about his victory over Wilson, after which he celebrated enthusiastically by punching the air a number of times, hand-slapping a fan in the front row and blowing a kiss to the crowd.

'The Rocket' was 5-1 up in the match, before being pegged back in the first session, but a blistering second session with breaks of 124, 90, 83 and 74 saw him advance.

The 41-year-old goes in search of his sixth world crown, as he looks to equal Stephen Hendry's record of 18 'Triple Crown' event wins.

"I like to play for the fans, I get a kick out of it," he added. "It is about entertaining and put in good performances. That is the most important thing.

"I do not need to prove anything to anybody, I have won five worlds, seven Masters and five UK titles and I'm only one behind Hendry on the majors list. Another world title will not make a massive difference.

"I would love to win another world title but it is about working with people I enjoy working with and getting some satisfaction by playing with freedom."