Kendrick Lamar had no idea his Taylor Swift collaboration 'Bad Blood' was written about her rumoured feud with Katy Perry.

The 'Humble' rapper lent his talents to the 2015 hit single - taken from her hugely popular '1989' album - and has claimed he wasn't aware of the suspicions that the track was penned about the singers' public row.

Asked if he knew about the potential subject matter, he told Rolling Stone: ''No, I wasn't aware of that, bro... No! On the record, no. Which makes it even more funny now, for sure.''

Lamar admitted any kind of ''real beef'' is something he wants to avoid, not got involved in.

He added: ''That's far beyond my concern. I have to stay away from that, for sure. That's some real beef.''

Swift and Perry's feud kicked off four years ago, when the latter allegedly hired backup dancers from her rival's tour, with the 'Shake It Off' star hinting at the drama in a 2014 interview.

Not naming the 'Roar' singer directly, she said: ''She basically tried to sabotage an entire arena tour. She tried to hire a bunch of people out from under me.''

Earlier this year, Perry opened up on the feud during her appearance on 'Carpool Karaoke'.

She admitted: ''There's a situation. Honestly, it's really like she started it, and it's time for her to finish it.''

Last month, Perry claimed she loves Swift and while they've clashed, she wishes her all the best on ''her journey'', even if they're taking different paths.

She recently said: ''I love her, I always have. We've had our differences but I just continue to say, 'God bless her on her journey.' ''