A transparent dress which helped Kate Middleton to catch Prince William’s eye while she was at university is to be sold at auction.

The see-through knitted lace dress is expected to fetch £8,000 when it goes under the hammer next month.

Ms Middleton strode down a catwalk wearing the dress and black underwear during a charity fashion show at the University of St Andrews in 2002.

Prince William was in the audience and the pair later became a couple. The garment, which was designed by student Charlotte Todd, was initially created as a skirt, but the show’s organisers decided it would be worn as a dress.

Ms Todd said: “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.”

A spokesman for Kerry Taylor Auctions said the dress is expected to fetch between £8,000 and £10,000.

The Passion For Fashion auction, which will be held in central London on March 17, also includes two gowns worn by Prince William’s mother, Diana, Princess of Wales.

One garment, a Zandra Rhodes pink chiffon dinner gown which was worn on a state visit to Japan in 1986, is expected to fetch between £30,000 and £40,000.

A Catherine Walker formal white lace evening dress, worn on a state visit to France in 1988, is expected to sell for at least £40,000.