John Virgo has apologised after he was heard swearing on air during a semi-final at the World Snooker Championship. The 70-year-old thought he was holding an off-microphone conversation but could be heard muttering during the match between Mark Selby and Marco Fu.

He said during BBC One’s live mid-afternoon broadcast: “I wanted to watch a bit of racing this afternoon. I’ll be lucky to watch some fucking Match of the Day.”

His comments came while Selby and Fu were contesting the longest frame in Crucible history, which ran to one hour and 16 minutes. IMG Media produces the BBC’s Crucible coverage, and its managing director for global production, Graham Fry, said Virgo would continue to work at the tournament but had been spoken to about the incident.

Fry said of the former UK champion: “It was off-mic, the mics weren’t switched on and it somehow got picked up. It was a mistake and I’ve spoken to him about it. He’s embarrassed and apologetic.”

Virgo was snooker’s UK Championship winner in 1979 but is equally well known as a television personality, having presented the popular BBC One show Big Break alongside Jim Davidson from 1991 to 2002.