John Lennon's widow Yoko Ono has authorised film-makers to use previously unseen footage of the late beatle in a new documentary. THE US VS JOHN LENNON follows the period of Lennon's life, between 1966 and 1976, when he was an anti-war activist and had trouble qualifying for American citizenship. Ono provided directors DAVID LEAF and JOHN SCHEINFELD access to home movies, wedding photographs and unfinished films. She says, "Of all the documentaries that have been made about John, this is the one he would have loved." Leaf adds, "It's definitely a forgotten story. The vast majority of people who lived through that period and knew something about the Lennon case haven't thought about it in a really long time. For anyone born since then, it's probably an unknown story." The US Vs John Lennon is receiving its world premiere at the Venice Film Festival in Italy. Lennon was assassinated in 1980.