Charles and Diana's wedding cake for sale

A slice of Prince Charles and Princess Diana's wedding cake is set to be sold at auction.

The slice of 30-year-old iced fruitcake has been put up for sale by a New Zealand woman Katrina Greenslade on auction website Trade Me, after she claimed her father was given the cake while working at an airbase in Christchurch in 1981.

Katrina wrote on the auction site: "The story goes that one of the wedding cake tiers was given to the RNZAF (Royal New Zealand Air Force) and one fifth came to Wigram and was divided up so that as many people as possible would get a taste.

"Lots were drawn and those whose name came out of the hat were allowed a minuscule piece.

"My father won a bite and he joined the queue near the end of the tasters and sitting left on the plate was a piece of icing. He took this icing, instead of a little piece of the cake he was offered, and took it home to show us."

The seller - who claimed a similar slice, but with a Royal Crest on it, sold in the UK for £1,000 - admitted that the icing has discoloured and come away from the fruitcake.

It has sat for the past four years in a Tupperware container in the drawer of her china cabinet.

She told New Zealand newspaper The Press: "It smells like a piece of 30-year-old cake that has lived in a Tupperware container."

So far the cake's highest bid is £28 with bidding closing on January 19.

Comments next to the auction range from "very gross" to "truly amazing story and auction! God save the Queen."