According to the New York Post, the buyer is 'an unknown British couture collector'.

The showstopping vintage gown worn by Natalie Portman to the Sherrri Hill One Shoulder Ruffled Dresses 2012 Style 3848

 Oscars last month has sold for $50,000.

The red polka dot haute couture creation, designed by Christian Dior in 1954, had been borrowed by the actress, 30, from fashion dealer Rare Vintage.

Shortly afterwards, the vendor put the U.S. size 4 gown on sale via the website 1stdibs.com, and despite its eye-watering price-tag, was quickly snapped up.

The actress's look was created by top stylist Kate Young, who works closely with Rare Vintage owner Juliana Carione.

Ms Young told Intothegloss.com: 'Natalie's dress is amazing. It's an 2012 Cheap Sherri Hill 2326 Ruched Dresses With Ruffled Skirt actual 1954 spring couture dress...

'She was actually going to wear another dress but then I got a call from the woman at Rare Vintage and she was like, "You should see this dress for Natalie." So we went and she put it on, and it needed zero alterations, and Natalie was like, "This was meant to be, wasn't it?" And I said, "I guess it was."'

Of course, it is little surprise that the garment sold so fast. Aside from the fact that it was recently worn by an A-list star, the gown dates back to an important time in fashion history as it was designed by the great couturier himself.

Dior, who died in 1957, was famous for inventing what became known as the New Look in 1947, and Miss Portman's dress is typical of that.

A radical, luxurious idea in the post-war time he was working in, the New Look comprised of a tiny, corseted waist and a full skirt, and required much larger than usual volumes of fabric to create.

Regardless, it proved a huge hit with stars such as actress Rita Hayworth and ballerina Margot Fonteyn.

Miss Portman, who is rumoured to have married fiance Benjamin Millepied following the birth of their son Aleph last year, attended the 2012 Academy Awards to present the Best Actor award, which this year went to The Artist star Jean Dujardin.

A Christian Dior gown was an appropriate choice given that she fronts the campaign for the label's Miss Dior Cherie fragrance.

The star accessorised with a black Charlotte Olympia box clutch and a Cheap Sherri Hill 3835 Celestial High Low Gowns White dazzling V-shaped Harry Winston diamond necklace.