A SOLID gold egg won as part of nationwide competition run by Cadbury's 30 years ago is expected to be sold for thousands of pounds when it is auctioned off in the new year.

The three inch-tall, 22-carat egg was one of 12 commissioned by the chocolate maker for its Crème Egg Mystery Conundrum, which was held in 1983.

Cryptic clues contained in a specially published book were meant to guide egg hunters to a dozen secret locations dotted around the country where they could dig up a casket containing a certificate, entitling them to claim the valuable prize.

However, the competition proved so popular it had to be called off before all the caskets had been found after thousands of people started digging up private land and historic sites.

One of the caskets was buried in the grass verge of the A66 west of Bowes.

A local resident worked out the clue to its whereabouts and claimed the egg, which has been in his possession ever since.

Now, the egg's owner, who wishes to remain anonymous, has decided to sell the prized possession and contacted Barnard Castle-based TV antiques expert David Harper for help.

Mr Harper said one of the clues led many people to the grounds Bowes Castle, where they started to dig.

“It wasn't there, but a lot of people thought this was the logical place to put it,” he said.

“The country went mad for the competition and it ran out of control.

“The chap who found the casket said he literally tripped over it. It's been in his possession ever since. He just walked into the shop with it.”

The egg was made by Garrards – jewellers to the queen – and was called The Burning Hand. It was number 10 of the 12 made for the competition.

Mr Harper has entered the egg into a specialist sale of 20th century goods which will be held in Cheshire on January 28-29.

Its estimated value is between £6,000 and £8,000, however given the story behind the egg, it could make much more.