In a recently released video, the Thirty Seconds to Mars frontman critiques the pop star's music while listening to songs of hers in a recording studio.

During the session, Leto states, "Oh, I don't like this at all. Next," as he listens to Taylor's Welcome to New York, before offering praise for her track Blank Space, adding, "I like this verse, actually."

However, towards the end of the video, the Dallas Buyers Club star grows disenchanted with Swift's 1989 album altogether, commenting, "F**k her. I don't give a f**k about her."

Fans quickly took aim at Leto for criticising Swift, but he has since apologised, insisting he has nothing personal against the 25 year old.

"The truth is I think @taylorswift13 is amazing + an incredible example of what's possible," he writes on Twitter.com. "If I hurt her or her fans my sincerest apologies."

Leto hasn't actually taken back his initial comments.