A risque dress worn by Kate Middleton, which is said to have caught he the eye of husband-to-be, Prince William, is going to be auctioned.

Kate Middleton donned the infamous see-through dress in 2002 as she walked down a catwalk at a charity fashion show at the University of St. Andrews.

It was reportedly that dress, and that show, which made Prince William, who may have drooled a little in the front row, want to get more involved with his friend and flatmate.

The thought of it had royal-watchers in right tizz.

Now the designer of the dress, Charlotte Todd, is auctioning it off on March 17th.  At that same auction will be two dresses worn by Prince William’s late mother, Princess Diana.

“The dress was meant to be a skirt,” says  Todd.

“I don’t know whether Kate was given it to wear or whether she chose it. If it was her idea to wear it as a dress, she was very brave.”

Commenting on the role her dress had on Prince William and Kate Middleton’s royal romance, Todd added: “If it is true that my design helped change the Prince’s interest in Kate from platonic to romantic as has been reported, then I am pleased to have played a part – however minor.  I never would have imagined as I sat knitting this piece that one day it would be so important.”

Todd did not pursue a career in fashion, but works at an aquarium. She had never intended to sell the dress, but eventually realised she had no reason to keep it.

The carefully woven number cost just £30 to make – and it’s expected to fetch up to £10,000 at the auction on March 17 – so you can’t really blame her.

“I was keeping hold of the dress,” Charlotte tells The Mail On Sunday.

“I just had a feeling that it was the right thing to do.

“But as the years went on I just thought, ‘Oh well, nothing’s going to happen?’”

“The dress was squashed in a wardrobe underneath loads of junk.

“Now it’s quite a responsibility – people are really interested in the dress.

“I didn’t let anyone try it on because it’s so fragile.

“It was just pure luck that Kate, out of all those girls, wore it for a few seconds.

“I don’t even see it as a dress, really. To me it’s just a piece of fabric.”

The famous little number goes up for auction at Le Galleria on Pall Mall on 17 March at 2pm.