A diamond-studded crystal Fabergé egg that once belonged to Russia's imperial family has sold for a record £22.9m ($30.2m) in London.

The Winter Egg - considered one of the legendary jeweller's most beautiful creations - was bought by an anonymous bidder on Tuesday, Christie's auction house said.

It is decorated with 4,500 diamonds and was commissioned by Tsar Nicholas II in 1913 as a present to his mother.

The previous record for a Fabergé egg was £8.9m paid at auction in 2007.

"Today's result sets a new world auction record for a work by Fabergé, reaffirming the enduring significance of this masterpiece," Christie's Margo Oganesian was quoted as saying by the AFP news agency.

The 8.2cm high (3.2in) egg was created by Carl Fabergé, based on the design of Alma Theresia Pihl, one of only two female workmasters at St Petersburg's jewellery company.

It was carved from rock crystal and decorated with rose-cut diamonds, as well as platinum snowflake motifs.

The egg opens up to reveal a tiny basket of white quartz flowers inside.

The Fabergé house only ever made 50 eggs for Russia's imperial Romanov family, and the Imperial Winter Egg is one of just seven left in private hands.

The others are either missing or owned by institutions or museums.

The eggs were made from 1885 until Tsar Nicholas II was forced to abdicate in 1917.