The figure-hugging gown Marilyn Monroe wore to serenade US President John F. Kennedy on his 45th birthday smashed its guide price to sell for $4.8 million at auction on Thursday.

The flesh-colored dress, adorned with 2,500 hand-stitched crystals, had been expected to fetch between $2-3 million, Julien's Auctions in Beverly Hills said.

It went to Ripley's Believe It or Not!, an American media empire specializing in bizarre and historically significant items which owns a chain of museums, including one in Hollywood.