The BBC presenter was previewing the third-round replay in a studio at Molineux alongside pundits Paul Ince and Danny Murphy when awkward and audible pornographic wails broke out in the background.
Lineker looked momentarily startled by the prank and struggled to keep a straight face thereafter as he cut to colleague and fellow former England striker Alan Shearer in the commentary gantry.
Lineker tried to laugh off the incident as the noise continued to blare out and said to Shearer: "Somebody's sending something on someone's phone, I think. I don't know whether you heard it at home."
Once the match had begun, Lineker revealed the cause, tweeting a picture of a mobile phone and three laughing emojis alongside the words: "Well, we found this taped to the back of the set.
"As sabotage goes it was quite amusing."
Liverpool scored the only goal of the first half, and during the half-time analysis, Lineker said to Ince and Murphy: "Harvey Elliott's goal was a screamer… which was not the only one we've had tonight."
The stunt did not go unnoticed by viewers as the incident was clipped and widely shared on social media.
A BBC spokeperson said on Twitter: "We apologise to any viewers offended during the live coverage of the football this evening. We are investigating how this happened."