The sheer, figure-hugging dress Marilyn Monroe wore to serenade President John F. Kennedy for his 45th birthday has sold for a record $4.8 million.

With a pre-sale estimate of $3m, the flesh-coloured dress went under the hammer at Julien’s Auctions in Los Angeles and was snapped up by museum chain Ripley’s Believe It Or Not.

“We believe this is the most iconic piece of pop culture that there is,” Edward Meyer, vice-president of Ripley’s Believe It Or Not told the Press Association.

“In the 20th century I cannot think of one single item that tells the story of the 1960s as well as this dress. It’s a new world record for a dress.”

Monroe sang happy birthday in front of 15,000 guests at New York’s Madison Square Garden (Rex)

Outselling the previous most expensive dress sold at auction – Monroe’s white gown from The Seven Year Itch which went for $4.6m in 2011 – it was presented on a custom-made mannequin designed to match the actresses exact body measurements.

Featuring more than 2,500 hand-stitched crystals, the dress was so tight fitting that Monroe was said to have been sewn into it before she performed for Kennedy on 19 May 1962.

The act sparked rumours of an affair between the pair and it was one of her last public appearances before her untimely death.

Unseen photographs of Marilyn Monroe Show all 8 1 /8 Unseen photographs of Marilyn Monroe Unseen photographs of Marilyn Monroe Marilyn Monroe poses with a grizzly bear in this previously unseen photo taken in Alberta, Canada in the summer of 1953 Reuters Unseen photographs of Marilyn Monroe Actress Marilyn Monroe takes time out from filming River of No return with Robert Mitchum after spraining her ankle Reuters Unseen photographs of Marilyn Monroe Actress Marilyn Monroe with her fiancé and baseball legend Joe DiMaggio Reuters Unseen photographs of Marilyn Monroe An injured Marilyn Monroe sits beside a swimming pool with a sprained ankle Reuters Unseen photographs of Marilyn Monroe Marilyn Monroe strikes a pose on location in Banff, Canada Reuters Unseen photographs of Marilyn Monroe Marilyn with another wild animal in Alberta, Canada in the summer of 1953 Reuters Unseen photographs of Marilyn Monroe Marilyn Monroe reaches for the sky in just one of over 100 previously unseen photos taken by John Vachon in Alberta, Canada Reuters Unseen photographs of Marilyn Monroe Not one to shy away from the camera, Marilyn Monroe takes some of her own photos Reuters

“This dress, this story, this momentous occasion represents a defining moment in history,” said Martin Nolan, executive director of Julien’s Auctions.

“This auction will remind the world why Marilyn Monroe remains an icon.”