O'Sullivan is a two-time winner at The Crucible

O'Sullivan will play rising star Ding Junhui in the first round in Sheffield.

"My first thought was 'that's a hard one'. My next was 'someone's fixed the draw'," O'Sullivan told Zoo magazine.

But a World Snooker spokesman said: "It was 100% genuine - the balls were drawn randomly by two BBC presenters and there was an independent auditor."

Reigning world champion Graeme Dott backed the stance of the tournament's organisers, but he also expressed some sympathy for O'Sullivan.

"There's no way it's been fixed, although I'd have probably said the same if I'd drawn Ding," said the Scot, who will play Ian McCulloch in round one.

"He's drawn Ding and he's just got to get on with it."

The draw for snooker's flagship tournament was carried out on the BBC's Breakfast programme last month.

O'Sullivan's match-up with Ding, a repeat of January's Masters final, was the stand-out tie of the draw.

Ding has soared up the world rankings in the last two seasons, and is rated among the favourites for the title in Sheffield on his Crucible debut.

Whoever is doing the draw is trying to stitch me up Ronnie O'Sullivan

O'Sullivan, who won at The Crucible in 2001 and 2004, has faced tricky opponents in his first-round matches in recent years.

He lost to Marco Fu in the opening round of the 2003 tournament, and had to beat Scotland's Stephen Maguire in 2004 and 2005.

Last year, the former world number one eased to a straightforward 10-4 win over Dave Harold.

"I've had Marco Fu, Stephen Maguire twice and now Ding in the first round," said O'Sullivan.

"It's definitely fixed. Whoever is doing that is trying to stitch me up."

The top 16 players in the world rankings qualify automatically for the tournament, and are kept apart in the opening round.