World snooker chairman Sir Rodney Walker maintains Ronnie O'Sullivan will be asked to explain his walkout at the Maplin UK Championship.

'The Rocket' stunned everyone at the Barbican Centre in York on Thursday when he conceded his quarter-final against Stephen Hendry after only five frames, before promptly leaving the arena.

O'Sullivan, 31, subsequently issued a statement expressing regret for his actions, in which the world number three claimed he would be back at the snooker table in the near future determined to erase the memory of this week.

Walker, head of the World Professional Billiards and Snooker Association, feels the incident will have done little to enhance the reputation of the game and expects the governing body to pursue the matter with the two-time world champion.

''I was at least pleased and relieved that within a very short period of time a statement was issued on Ronnie's behalf apologising to the spectators, the viewers and Stephen Hendry for his behaviour,'' said Walker.

''But it ought not to have happened in the first place.''

Walker told BBC Radio Five Live's Sportsweek Programme: ''The professional players know we are beginning to rebuild the sport.

''Incidents like this do nothing to give sponsors and spectators confidence to invest in the sport.

''I am sure the chairman of the disciplinary panel will write to him inviting him to give an explanation.''

It was another colourful chapter to the story of a career loaded with controversy for O'Sullivan, who claimed last year he would ''rather be planting a few shrubs in the garden'' than playing at the Grand Prix in Preston.

Walker added: ''Ronnie from time to time does suffer from depression and things of that nature.

''We owe it to the fellow to at least give him the chance to explain to us what state of mind he was in when he walked out.''

However, Walker did not rule out the possibility of sanctions against O'Sullivan.

''We will do whatever is appropriate,'' he said.

''We are not frightened of him, but if there is a way to help to refocus I would rather do that than hit him with a stick.''

Walker added: ''At some stage I suppose you begin to run out of patience. I doubt whether we have reached that stage yet.''