The Oscar awarded for the script of a film regarded as one of the best ever made, Citizen Kane, has been sold in California for $US861,542.
The award was won by Orson Welles, who directed and starred in the 1941 film, which tells of one man's ruthless pursuit of power.
It was nominated for nine Academy Awards, but won in only one category - best original screenplay, the BBC reports.
The statuette, Welles' only Oscar, was once thought lost but resurfaced in 1994 when an American man tried to sell it. Cinematographer Gary Graver claimed Welles had given it to him as a form of payment.
Numerous legal battles ensued before Welles won back the rights of ownership.
The identity of the online bidder has not been revealed. But the auction house said the second-highest offer came from magician David Copperfield.
Academy Awards very rarely come up for sale. Since 1950, the academy has required Oscar winners to sign an agreement that they will never sell their statuette.
In 1999, singer Michael Jackson paid $1.54 million for the Oscar given to David O Selznick for producing Gone With The Wind.