A game of two halves, one cup: Porn plays in BBC studio before Wolves vs Liverpool FA Cup tie

When Ruud Gullit coined the term "sexy football", this isn't what he had in mind.

Shocked BBC viewers were treated to a phwoar-nil before a ball had even been kicked on Tuesday night.

The sound of someone scoring played over presenter Gary Lineker's introduction of commentator Alan Shearer before Wolves took on Liverpool in the FA Cup.

An X-rated porno soundtrack seemed to be emanating from the BBC Match of the Day Live studio, with a bemused Lineker holding back giggles as he struggled to make himself heard.

"I don't know who's making that noise," Lineker said, as he looked around confused.

Speaking to Shearer, stationed in the commentary gantry, he continued: "Alan, it's toasty in the studio. It's noisy, too – I don't know if someone's sending something on someone's phone..."

After a brief pause, the embarrassing noise continued, playing over the pair's conversation before the definitely pre-watershed 7.45pm kick-off.

Eventually, the culprit was identified – albeit off-screen.

Shortly after kick-off, Lineker tweeted out a photo of a cheap-looking mobile phone covered in sticky tape.

"Well, we found this taped to the back of the set," the former England striker said. "As sabotage goes it was quite amusing."

It seems it was a sophisticated booby-trap, with a true-blue smut supporter somehow playing a filthy film at full-volume down the line.

Twitter users were unsurprisingly delighted with the raunchy gag, with football journalist Si Lloyd tweeting that he had been "genuinely worried Danny Murphy was having the time of his life out of shot".