Editor’s Note: This article was updated with the final price and other details following the auction’s conclusion.

London CNN  — 

An original “Star Wars: Episode V – The Empire Strikes Back” script, which reveals how a pivotal plot twist was hidden from actors, smashed auction estimates to sell for £23,000 ($32,000).

Once belonging to Darth Vader actor David Prowse, and marked “Vader” at the top of each page, the incomplete script was auctioned by East Bristol Auctions in the UK on Tuesday – or May the Fourth, a date celebrated annually as “Star Wars Day.”

Prowse, who died in November aged 85, wore the black suit and helmet to play Vader in the original “Star Wars” trilogy.

But it was the actor James Earl Jones who provided the character’s voice – and who delivered one of Vader’s most famous lines to Luke Skywalker, telling the young Jedi: “I am your father.”

However, the script provided to Prowse omits this key revelation and shows different lines in its place.

“Luke, we will be the most powerful in the galaxy. You will have everything you could ever want… do not resist… it is our destiny,” the script given to Prowse reads.

The script belonged to Darth Vader actor David Prowse.

Prowse’s script was the top earner during a Star Wars-themed auction that netted a total of £400,000 ($556,000). Other highlights included a signed Mark Hamill photo, which sold for £15,000 ($21,000), and a signed Carrie Fisher picture that went for £11,000 ($15,000).

A cast list and a replica lightsaber sold for £10,000 ($14,000) each.

In a press statement, Andy Stowe, auctioneer at East Bristol Auctions, described the results as “truly out-of-this-world,” adding that the auction had attracted over 2,000 international bidders.

Calling Prowse’s script “an incredible part of our world history,” Stowe said the final sale price was “remarkable, but unsurprising.”

“Its not just a piece of movie memorabilia, but its actually an incredible part of our world history – this is THE script used on-set, during the most beloved film in the franchise,” the statement read.

Ahead of the auction, Stowe told CNN the revelation that the two characters were father and son was considered to be top secret.

“The only people that knew I think were about three or four members of the cast,” he said.

US actor Jones delivered the “Star Wars” villain’s lines after Prowse’s West Country English accent was thought to be unsuitable for the part.

According to auctioneers, during filming of the 1977 movie “Star Wars: Episode IV – A New Hope,” Prowse believed that he would be the voice of Vader, and was surprised to learn his lines had been dubbed.

“He was very much hired for his physical attributes,” said Stowe.

Prowse had a passion for bodybuilding and was crowned British Weightlifting Champion several times in the 1960s. His broad physique and towering figure helped land him roles as monsters and villains in TV shows and movies, including the monster in “The Horror of Frankenstein” in 1970 and a bearded torturer in “Carry on Henry” in 1971.

Correction: An earlier version of this story included a photo of Mark Hamill and stuntman Bob Anderson, who was misidentified by Alamy photography agency as Dave Prowse. The photo has been removed.

CNN’s Angela Dewan and Samantha Beech contributed reporting.