Ammon News - A speckled egg dating back to Roman times still has its liquid yolk and whites inside intact, new analysis shows.

The 'rare and exciting' artefact, which dates back 1,700 years, was found in Berryfields to the north-west of Aylesbury in Buckinghamshire.

About 1.5-inch (4cm) wide, it was in a waterlogged pit, which is thought to have helped the egg's incredible preservation.

Dana Goodburn-Brown, archeologist at DGB Conservation, carried out a micro CT scan on the egg, which confirmed that it is still full of liquid and an air bubble.

'It was an exciting moment when we first saw the air bubble inside, and then decided to turn the egg and look again, to see if the bubble would move, which it did,' she told MailOnline.

'We decided it is best to not undertake any invasive treatment for the egg because it is so rare and its contents are possibly of huge scientific value.

'Eggshells are porous and anything put onto the eggshell surface might also contaminate the inside contents.'

Eggshells have been found in other UK Roman sites before – but never a complete egg, let alone one with liquid preserved inside.

The egg was one of four discovered during excavations at Berryfields between 2007 and 2016 in advance of a new housing estate.

The were part of an 'extraordinary' collection of items, which also included a woven basket, pottery vessels, coins, leather shoes and animal bone.

However, three of the eggs broke releasing a 'potent stench of rotten egg', described as 'unforgettable' and 'incredibly sulphurous' by those present.

According to Mrs Goodburn-Brown, the egg was likely preserved as a result of being placed in a waterlogged pit.

'Organic materials and liquids do not normally survive the depths of time unless in special circumstances, such as being sealed by clay or mud and no oxygen circulating,' she told MailOnline.

'The waterlogged conditions at the Buckinghamshire archaeological site preserved the eggs in situ, as well as the nearby remains of a fragile wooden basket.'

Oxford Archaeology, which oversaw the excavations, said someone may have placed the eggs inside the basket and into a Roman well for good luck, much like today's wishing wells.

In Roman society, eggs symbolised fertility and rebirth, so it may have been somehow linked to another object placed there at the same time.

The egg was recently taken to London's Natural History Museum to gather expert opinion from Douglas Russell, the museum's senior curator of birds' eggs and nests.

Mr Russell said the 'fascinating' and 'possibly unique' object was likely 'unintentionally preserved by the soil conditions in which it was found'.

'There are older eggs with contents – for example, the NHM has a series of mummified birds' eggs, probably excavated by Sir Flinders Petrie from the catacombs of sacred animals at Denderah, Upper Egypt in 1898 which may be older.

'However, this is the oldest unintentionally preserved avian egg I have ever seen. That makes it fascinating.

'Going forward, it will be very exciting to see if we can use any of the modern imaging and analysis techniques available here at the NHM to shed further light on exactly which species laid the eggs and its potential archaeological significance.'

The egg is now being housed at Discover Bucks Museum in Aylesbury.

Researchers are now aiming to extract the liquid contents from the egg without breaking the shell, although exactly how this will be done is another matter.

One option could be making a fine incision in the shell to drain the contents, although this could cause.

'It's a bit like blowing an egg – but obviously a much finer process,' Edward Biddulph, senior project manager at Oxford Archaeology, told the BBC.

'There is huge potential for further scientific research and this is the next stage in the life of this remarkable egg.'

Daily Mail