Unreleased John Lennon material surfaces

Previously unreleased John Lennon material is to feature on the soundtrack of a forthcoming documentary.

A live version of 'Attica State', recorded at the John Sinclair Freedom Rally in Ann Arbor, Michigan, in 1971, and the film's instrumental version of 'How Do You Sleep' will appear in 'The US vs John Lennon'.

Classics including likes of 'Imagine', 'Instant Karma (We All Shine On)' and 'Happy Xmas (War is Over)' are also set to feature, reports Billboard.

The soundtrack will also include liner notes written by Lennon's widow Yoko Ono.

The documentary explores the US governments's attempts to gag the late singer's humanitarian and anti-war causes through archival film footage and Lennon's music.

David Leaf, who co-wrote, directed and produced the film along with John Scheinfeld, said: "We were allowed to 'strip' lead vocals from Lennon's original recordings, so that we could use his own instrumental work as the score for the movie. I think it's the first time that John's solo catalogue can be heard in this way."

'The US vs John Lennon' soundtrack is slated for a US release on September 26. The documentary will follow at the end of the month.

A UK date for both releases is still to be set.