Orson Welles' 'Citizen Kane' Oscar has been put up for auction.

The late actor-and-director's Best Writing (Original Screenplay) accolade that he shared with Herman J. Mankiewicz for their work on the 1941 movie is set to go under the hammer at the Nate D. Sanders auction house with a reserve price of between $600,000 to $1 million.

The statuette has recently been the subject of a court dispute which saw Orson's daughter - who had recovered the gong from a cinematographer who claimed the legendary actor had given him the Oscar as a present - overcome an attempt from the Academy of Motion Picture Arts and Sciences to block the item from going on sale.

Los Angeles auctioneer Nate revealed bidding for the gong - which went on sale in New York four years ago but failed to find a bidder - will end on December 20.

He said: "Orson Welles's Oscar was awarded for the best screenplay, and incredibly, it's the only Oscar that 'Citizen Kane' received."