WENN

Lady Gaga launched a foul-mouthed rant at fans on Saturday night, after they reportedly heckled her with calls of "Where's Bradley?"

Questions about the nature of the singer/actress' relationship with Bradley Cooper, with whom she starred in Oscar-winning movie A Star Is Born, were fuelled when the pair put on an intimate performance of Shallow at the Academy Awards earlier this year.

The duet earned the pair a standing ovation with their stunning rendition of the song, but fans began speculating as to whether there was anything romantic between Gaga and Bradley – despite the fact that Irina Shayk, the mother of Bradley's two-year-old daughter Lea, was in the front row.

The Born This Way hitmaker insisted at the time that the passion between her and Bradley was just an act, but following the actor's reported split from his model partner, the questions have once again been raised.

According to Britain's The Sun newspaper, as Gaga took to the stage in Las Vegas on Saturday, she was heckled by calls from the audience asking where Bradley was.

And the star wasn't too happy about the catcalls – just before she performed Shallow, she told the crowd: "And one more thing, be kind or f**k off."

Gaga split from her fiance Christian Carino in February, with the break-up announced shortly before her and Bradley's duet at the Oscars.

As she addressed rumours that her friendship with Bradley may have led to the end of her betrothal, Gaga responded: "Yes, people saw love. And guess what? That's what we wanted you to see."