LOS ANGELES: The Oscar statuette given to Orson Welles for his critically-acclaimed masterpiece “Citizen Kane” is being sold at auction this month, organizers said Monday.

Bids for the slightly-tarnished golden Oscar for 1941 best screenplay – worth an estimated $1 million – will end on December 20, said Los Angeles auctioneer Nate D Sanders.

The statuette failed to find a buyer when offered for sale in New York four years ago, but auctioneers are confident in the interest for the iconic movie's illustrious prize.

“Orson Welles's Oscar was awarded for the best screenplay, and incredibly, it's the only Oscar that 'Citizen Kane' received,” said Sanders.

Despite some tarnishing on the legs, the Oscar is “overall in very good condition,” he said, calling it “a spectacular tribute to the visionary director and screenwriter, Orson Welles, and to the film he brought to life.”

“Citizen Kane” was Welles's first feature, made when he was just 25 years old. Considered a masterpiece of cinema, it has been voted the top film in history by both the American and British Film Institutes.

The film – which did poorly at the box office and failed to win a nomination for best picture – tells the story of a newspaper magnate bent on supremacy and is thought to be based on US press baron William Randolph Hearst.

Although “Citizen Kane” received Oscar nominations for best screenplay, best director and best leading actor, the writing award was the only Oscar awarded to Welles throughout his life.

The history of the statuette has included some hazy spells: Welles believed he had lost it, but it resurfaced after he died in 1985, and was bequeathed to his daughter Beatrice in 1994.

In 2002 she won a legal case against the Academy of Motion Picture Arts and Sciences giving her the right to sell it. During that court case the statuette was valued at $1 million, Sanders said.

The Oscar was offered for sale at Sotheby's in New York in December 2007, but failed to find a buyer. It was then being sold by a US charitable foundation, which acquired the golden statuette from the Welles estate.

The statuette – 12 inches tall, and weighing 7 pounds and 5 ounces – is being sold from a private collection, Sanders said, adding that the winning bidder will also be given a complete chain of ownership record.