A replica of Princess Diana's wedding dress sold at auction Wednesday for $175,000, twice its pre-sale estimate.

The ivory silk taffeta dress went to an anonymous private buyer, said a spokesman for auctioneer Cooper Owen.

The dress, complete with silk net petticoat, train one-third the length of the original, tiara and veil, was put up for auction by Madame Tussaud's waxworks museum in London. The museum had been in possession of the dress since immediately after the royal wedding between the then Lady Diana Spencer and Prince Charles on July 29, 1981.

"It's a very important dress," Owen said. "It's a dress that Diana personally said she wanted the world to see. She asked that a replica be made," he said.

The dress is identical to the original but does not include the antique Queen Mary lace that had been sewn on the front panel.

It is unclear whether Diana ever wore the dress. According to Madame Tussaud's former curator, Christina Bennett, Diana wore the dress during fittings for her wedding dress. But dress designers Elizabeth and David Emmauel said the second dress was made for the museum and Diana never wore it.

"Diana never tried the dress on, it was never a backup dress," Elizabeth Emmanuel said.

Diana's original wedding gown is on display at her family's country home near Northampton, central England.