Country songstress Taylor Swift has seemingly confirmed rumours her hit song 'I Knew You Were Trouble' is about ex-boyfriend Harry Styles.

Swift performed a dramatic rendition of the track at last month's BRIT Awards, where One Direction hunk Styles was attending with his bandmates Niall Horan, Zayn Malik, Louis Tomlinson and Liam Payne.

The blonde beauty insists she wasn’t bothered about performing the song in front of her former flame.

She told British newspaper The Sun: “It’s not hard to access that emotion when the person the song is directed at is standing by the side of the stage watching.”

Swift also spoke about her biggest frustrations when it comes to relationships.

She added: “There’s really no sound quite as loud as a phone not ringing, a letter unanswered. I don’t quite understand it, because I either want to be with you or I don’t. And we’re not going to mess things up by, like, accidentally making out.

“I’m not trying to scare you, I’m not pointing a gun at you – I’m offering to be with you.” Watch Swift's performance at the BRITs here: