A selection of gowns worn by Princess Diana have sold for over a million pounds (Picture: PA)

An assortment of gowns worn by Princess Diana have collectively sold for over £1,000,000 at an auction in the US.

A red Bruce Oldfield silk gown worn by Diana to a movie premiere in November 1991, sold for 571,500 US dollars (£458,484) at an event from Julien’s Auctions and Turner Classic Movies (TCM), in Beverly Hills, California.

The silk dress had been expected to sell for between 200,000 dollars (£160,000) and 400,000 dollars (£320,000).

The Legends: Hollywood And Royalty auction, featuring more than 1,400 items, celebrated 100 years of Warner Bros, and ended on Friday evening.

A Bruce Oldfield gown worn by Diana by a red carpet event in 1991 sold for over £450,000 (Picture: Getty)

The stunning dresses has not been seen in public for more than 30 years (Picture: Getty)

A black and jade gown by Catherine Walker – Diana’s personal designer for more than 16 years – which was worn by the late royal to a gala event in Toronto, Canada, in October 1991 was another top seller, also going for 571,500 US dollars (£458,484).

A custom-made black velvet and ivory gown, also designed by Walker, worn by Diana to a private function sold for 508,000 US dollars (£407,541), on an original estimate of 60,000 dollars (£48,000) to 80,000 dollars (£64,000).

The three designer dresses had not been seen in public for more than 30 years according to the auction house.

Martin Nolan, executive director and founder of Julien’s Auctions, said: ‘Buoyed by the tremendous success of this three-day sale – which brought in a record number of registrants and bidders from across the globe – we are already busy at work in the launch of our next Hollywood auction that will be a year-end spectacular as we celebrate Julien’s 20th anniversary.’

Other high-ticket items include a Givenchy couture pink evening dress, worn by Audrey Hepburn when she played Holly Golightly in Breakfast At Tiffany’s, which sold for double its original estimate at 444,500 US dollars (£356,598).

Collectibles from classic Hollywood actors Humphrey Bogart and his wife Lauren Bacall were also offered for the first time at auction.

The couple’s matching 14 karat gold wedding rings, exchanged by Bogart and Bacall during their wedding on May 21 1945, sold for 190,500 US dollars (£152,828) and a heart-shaped locket inscribed, ‘Baby, here’s my heart, Bogie’ went for 57,150 US dollars (£45,848).

Two dresses by Diana’s personal designer Catherine Walker also sold for over six figures at the auction (Picture: Julien’s Auctions/Mega)

The Hollywood couple’s son Stephen Bogart said: ‘My sister Leslie and I would like to thank Julien’s Auctions, Turner Classic Movies and Brooks Branch for their tremendous job bringing these important and dear artefacts to auction.

‘Everyone was so lovely to work with and TCM helped to put a wonderful spotlight on my parents’ legacy. Kudos to all.’

Science fiction film items such as Carrie Fisher’s production-made slave costume as Princess Leia from Star Wars: Return Of The Jedi was won by Fisher’s brother, Todd Fisher for 38,100 US dollars (£30,566).

The item had been estimated at 20,000 to 30,000 US dollars (£15,534 to £23,300).

‘We are very happy to add this piece to the estates’ collection of Debbie (Reynolds) and Carrie artefacts,’ said businessman Fisher.

‘We have been working with Darren Julien of Julien’s Auctions for many decades. He has helped us acquire some very important pieces, including my mother’s (Debbie) birthday cake outfit from Singin’ In The Rain.’

Fisher died at the age of 60 in December 2016 and appeared in 2017’s Star Wars: The Last Jedi posthumously, and through previously unreleased footage for 2019’s Star Wars: The Rise Of Skywalker.

Catherine Walker created garments for Diana for 16 years – including the black cocktail dress she was buried in – and her designs are still worn by royals today, including the current Princess of Wales, Kate Middleton (Picture: Julien’s Auctions/Mega)

American actress Reynolds, who was married to singer Eddie Fisher, appeared in classic Hollywood films such as What’s The Matter With Helen?, Charlotte’s Web and Halloweentown, before her death aged 84 in December 2016, just days after her daughter died.

The lightsabre used by Ewan McGregor as Obi-Wan Kenobi in Star Wars: Revenge Of The Sith also sold for 91,000 US dollars (£73,004).

Star Trek items such as a maroon Starfleet officer’s jacket worn by William Shatner as James T Kirk in Star Trek II: The Wrath Of Khan went for 127,000 dollars (£101,760).

All sale prices included the buyer’s premium.

The stunning collection of dresses had not been seen in public for over 30 years.