The British Broadcasting Corporation (BBC) issued an apology on Tuesday after its FA Cup coverage was interrupted by a pornographic audio clip.
Audio of a woman moaning was played at high volume just as host Gary Lineker was seeking the opinion of fellow pundit Alan Shearer ahead of Liverpool's 1-0 win over Wolverhampton Wanderers.
"I don't know who's making that noise," said Lineker with a laugh. "Somebody's sending something on someone's phone, I think. I don't know whether you heard it at home."
The former England striker later said a phone had been taped to the back of the studio set as a prank.
"As sabotage goes it was quite amusing," Lineker said on Twitter.
The BBC issued an apology, saying: "We apologise to any viewers offended during the live coverage of the football this evening. We are investigating how this happened."