Taylor Swift has released another surprise song "from the vault" ahead of the re-release of her album Fearless.

The pop superstar, 31, is re-recording her old music, starting with her 2008 record, following a high-profile and bitter row over the ownership of her early career masters.

She has already released her own version of the hit single Love Story and shared the first of six previously unreleased songs, a track called You All Over Me (From The Vault) featuring country music singer Maren Morris on backing vocals.

She has now released another track, which did not make it onto the final version of Fearless, called Mr Perfectly Fine.

She wrote on social media: "Me in 2020: life is chill, writing songs based in fiction to avoid drama, feeling pretty grown up.

"My 2008 music from the vault, in a goblin voice: 'REELEEEEEEASE MR PERFECTLY FIIIIIIINE."'

Me in 2020: life is chill, writing songs based in fiction to avoid drama, feeling pretty grown up

My 2008 music from the vault, in a goblin voice: "REELEEEEEEASE MR PERFECTLY FIIIIIIINE" https://t.co/PCexr31q9x

— Taylor Swift (@taylorswift13) April 7, 2021

Swift's re-recording spree was triggered by a row with prominent talent manager Scooter Braun.

He acquired the rights to Swift's first six albums in 2019, prompting a furious response from the singer. The masters have since changed hands again; Braun's company Ithaca Holdings sold them to Shamrock Capital in a deal announced last November.

Swift said she declined an offer to go into business with Shamrock because of Braun's continued financial involvement.

She moved to Universal Music Group in 2018 and has since released her album Lover, as well as surprise drops Folklore and Evermore.

Fearless (Taylor's Version) includes 26 songs, as well as a Love Story remix, while the original record included 13 tracks.

Explaining the new material, Swift revealed multiple songs were left off the original album for reasons including "too many break-up songs" and not being able to fit that much material on a physical CD.

She has already confirmed the titles of the previously unheard songs, including That's When, featuring country star Keith Urban.

Fearless (Taylor's Version) will be released on April 9.