The diamond jubilee rose gold egg, worth £100,000, is decorated with 60 gemstones - one for each year of the Queen's reign.

The unique egg - studded with diamonds, emeralds, rubies and sapphires - was created by Faberge and unveiled at the famous jeweller's central London boutique.

It is hoped the dazzling prize will attract enough participants to The Faberge Big Egg Hunt for it to break the record for the biggest.

More than 200 eggs - decorated by famous names including Bruce Oldfield, Sir Ridley Scott and Zandra Rhodes - were hidden across London on Tuesday as the hunt began.

Egg-hunters can enter to win the golden prize by texting a keyword found on each egg to 80001. There is one entry for each keyword texted.

The hunt is raising funds for charities Elephant Family and Action for Children and the decorated eggs used in the hunt will be auctioned when it finishes at Easter.

Elephant Family founder Mark Shand said: "The firing gun has sounded - let the hunt begin. Here's to an Olympic effort to win that diamond jubilee egg."

Action for Children chief executive Dame Clare Tickell added: "The Faberge Big Egg Hunt is an enchanting event which will capture the hearts, imagination and interest of everyone taking part. It's particularly heartening to know that money will be raised thanks to an event which will be hugely enjoyable for the thousands of children and families who will be taking part."

Sarah Faberge said: "We are thrilled to be involved in a fun-filled public project exploring creativity across so many artistic disciplines, and raising funds for two exceptionally deserving charities. I would personally like to thank all the artists involved."