Darth Vader's lightsaber from 'The Empire Strikes Back' set to fetch millions

Darth Vader's lightsaber, used to chop off Luke Skywalker's hand in Star Wars classic "The Empire Strikes Back", went on display in London on Wednesday, ahead of its US sale next month.

The prop has been described as the "Holy Grail" for Star Wars fans, with millions prepared to end up like Skywalker and give their right arm to own the iconic weapon.

Reflecting that passion, it is predicted to fetch up to $3 million went it goes on sale in Los Angeles next month.

"It's just an amazing piece of film history," Brandon Alinger, chief operating officer of the Propstore auction house selling the item, told AFP at a London preview of the sale's most important lots.

"Is there any villain as significant, as memorable as Darth Vader? I don't think so, and this is his weapon," he added.

Darth Vader wielded the "energy sword" during legendary fight scenes in both "The Empire Strikes Back" (1980) and "Return of the Jedi" (1983).

David Prowse, the actor behind Vader's mask, and stuntman Bob Anderson actually used two of the devices.

One without a blade was clipped to the villain's belt while the other, which had a wooden blade attached, was used for the fight scenes.

It is the battle-scarred item, albeit without the blade, that is up for sale, having been in the hands of a US individual for 40 years.

"Somebody, literally, who Googled 'sell Star Wars film prop' came to us and said, 'I've got this thing to sell', and we were just floored," explained Propstore founder Stephen Lane.

"There was no understanding that this thing even still existed -- it's a brand new discovery, which is incredibly exciting for Star Wars collectors."

He compared its significance to the ruby slippers worn by Judy Garland in 1939 classic "The Wizard of Oz".

Experts verified its authenticity by matching its dents and scratches to those seen on film.

"Look at the big dent on the back, that's probably from (Luke Skywalker actor) Mark Hamill's lightsaber blade," Alinger explained while showing the device to AFP.

While now likely worth millions, the item is actually an old camera-flash attachment with spare parts, such as the bubbles from behind a calculator pad, stuck on.

Other items to be sold during the three-day auction, taking place September 4-6, include the bullwhip, belt and holster used by Harrison Ford in 1989's "Indiana Jones and the Last Crusade".

One collector will also get their hands on a neuralyzer used by Agents J (Will Smith) and K (Tommy Lee Jones) to erase memories in "Men in Black" (1997).

"This is used in the opening scene of the film," explained Ibrahim Faraj, consignments manager at Propstore in the UK.

The item, whose LED display still works, is expected to sell for up to $150,000.