AN eggstraordinary hen left her owner’s brain scrambled when she laid a giant egg- with another fully formed egg inside.

Lilian Peart was amazed when she collected the eggs from her allotment at Bishop Auckland, County Durham, and discovered one three times bigger than a standard egg.

As if the size was not a big enough shock for Mrs Peart, when she cracked open the huge specimen it revealed another perfect egg inside.

The 68-year-old said: “I was expecting three, maybe four yolks, but never imagined that.

“Two eggs, one inside another is certainly a surprise.”

Mrs Peart and her husband, Amby, started keeping hens five years ago when granddaughter Sophie Hogarth, now 14, suggested they buy some chicks during a visit to a petting farm.

Since then Mrs Peart has fallen in love with the birds and currently has 36 hens of different breeds.

The star of the moment is Bluebell the Blue Haze, who produced the colossal egg on only her second lay since she was bought from Durham Hens, at Tow Law, County Durham.

It weighed in at an impressive 180g- three times more than an average egg of 53g to 63g.

Mrs Peart said: “I spend a fortune on them, I just love them.

“Bluebell was one of five I got on Mother’s Day this year, three were a present from my family, and I got two more while I was there.

“They keep the family going with eggs.”

Mrs Peart, from Auckland Park, Bishop Auckland, whisked the monster egg up as an omelette for husband Amby.

She said: “That’s his tea sorted.”

Margaret Manchester has managed hen and poultry supply business Durham Hens, at Tow Law, County Durham, with husband Alec for eight years.

She said: “We’ve seen a lot of eggs over the years but I have only seen one of these before.

“They are a hybrid hen so bred to lay lots of eggs but the size of that one was unusual but to get a fully formed egg inside is extremely rare.”

The cause of the phenomenon is called a counter-peristalsis contraction and occurs when the hen is in the process of forming an egg in her oviduct and another egg cell is released too soon.

A video of Mrs Peart cracking open the egg can be viewed at thenorthernecho.co.uk