Rare Cadbury's gold 'Conundrum' egg auctioned for £17,200

The 22ct gold Cadbury's egg, weighing 326.6 grams, was sold in Lincolnshire for £17,200

A rare 22ct gold Cadbury's Creme egg has sold at auction for more than it was initially valued at.

The enamel engraved egg was part of the chocolate firm's Creme Egg Mystery Conundrum treasure hunt in 1983.

It was sold for £17,200 at auction in Lincolnshire, but was expected to fetch only up to £15,000.

Twelve eggs were designed and made by Garrard & Co, the Queen's then official jeweller, but this one was a "secret" 13th that is larger than the rest.

Their whereabouts could be found by solving clues hidden in the accompanying Conundrum book.

The 326.6 g egg was made by Garrard & Co, for Cadbury's. of 22ct gold

Twelve gold eggs were created and hidden across the UK, but most people did not know that the 13th egg was also made.

It was bigger than the others, and featured a design encompassing 12 riddles that referred to the locations of the originals and based on the front cover of the book.

Every Cadbury retailer in the UK was entered in a draw during the Conundrum treasure hunt, and the winner won this egg.

The auction, held by Batemans of Stamford, was the first to hold it on public display.

The gold egg was sold in its original green embossed presentation box with a copy of Conundrum written by Don Shaw, illustrated by Nick Price, and published by Hamlyn in 1983

It was decorated with a star-studded sky, cat and weather vane

The 13th egg was won in a prize draw for Cadbury's vendors in 1983

Twelve gold eggs around the country could be found by solving clues from a book

Garrard & Co of London - the Queen's official jewellers at the time - was commissioned to create the 13 eggs in 1983