Ronnie O'Sullivan accused the snooker authorities of bullying and intimidating him in a breathtaking outburst at the Betfred World Championship.

The 41-year-old five-time Crucible champion pointed the finger at World Snooker chairman Barry Hearn and his board.

And he revealed the extent of his distress at receiving a letter from the sport's disciplinary panel after he criticised a referee and photographer during January's Masters.

Hearn last week criticised O'Sullivan, saying his recent behaviour in media interviews was "embarrassing".

O'Sullivan has deliberately and repeatedly given curt answers to questions he has faced after matches, while in an ITV interview at the World Grand Prix in February he gave a series of responses in a robotic voice.

This time O'Sullivan struck back, and said: "I phoned Barry up four weeks ago and I said, 'Look Barry, I'm done with all you and your board of people'.

"And I've got a very good friend of mine who said, 'Just let my lawyers deal with it'. I won't get involved with it because I'm not being bullied, I'm not having people doing that to me ever again.

"I like Barry but I'm not being intimidated or bullied any more."

O'Sullivan was speaking after launching his 25th Crucible campaign by beating Wallsend's Gary Wilson 10-7.

The Masters champion had two centuries and eight further breaks of above 50 against the debutant, but he is reluctant to open up about his matches.

"It's important that I keep focused, keep professional, keep myself out of trouble and just try to come and do a job," O'Sullivan said. "It's all about business.

"I have no problem with the press but sometimes I say things I shouldn't say and get myself in hot bother and I get a letter through saying I need to respond in 14 days, a day before a tournament and it's kind of messed up my last three or four tournaments."

O'Sullivan has been out of sorts since his Masters triumph at Alexandra Palace, failing to win back-to-back matches at the five events he has played between that tournament and his trip to Sheffield.

He blames World Snooker and the World Professional Billiards and Snooker Association, saying they have put him in the wrong frame of mind to play.

"I couldn't win a match really, and I thought that it's not fair on the fans, it's not fair on the people who have invested in me, and I don't really think I've done a lot wrong," O'Sullivan said.

O'Sullivan was unhappy with the performance of referee Terry Camilleri in his Masters semi-final win over Marco Fu, and said a press photographer had been "a f****** nightmare" during the match.

He says he was pushed over the edge by the reaction from World Snooker, having been incensed by previous disciplinary cases opened against him.

However, O'Sullivan was not fined for his Masters remarks after being asked to explain his criticisms.

"I've had it for five, six, seven years, and I'm just done with it," O'Sullivan added.

"They've pushed me a little bit too far and if I didn't have good lawyers to deal with it I'd probably walk away because I'm too old to be dealing with things like that.

"It's not that important. I could go and do Big Brother, I could go and do I'm A Celebrity... Get Me Out Of Here, I could have a great life doing other stuff. This is something I do for love, but I'm not going to do it and have people trying to intimidate me and bully me. I'm just not having it.

"I've given 25 years of service to this game and I think I've given enough. Drop me out, I don't need you, you probably don't need me."

Hearn has declined to respond to O'Sullivan.

Stuart Bingham built a 5-4 lead after his opening session against Peter Ebdon in a battle of former world champions that finishes on Monday.

Shaun Murphy held a 6-3 lead over Chinese 17-year-old Yan Bingtao following an entertaining opening to their contest. Yan became the first player born this century to play at the Crucible, and the winner of that clash plays O'Sullivan next.

Kyren Wilson wrapped up a 10-6 victory over Leeds potter David Grace, taking the closing three frames to seal his place in round two.