AN "elaborate and extraordinarily well-preserved" Roman villa has been discovered by chance by a home owner laying electric cables in his garden near Warminster.

The villa was found after rug designer Luke Irwin unearthed a high-quality Roman mosaic at his farmhouse while laying cables so that his children could play table tennis in an old barn.

He called in archaeological experts and an eight-day dig by Historic England and Salisbury Museum revealed the home of a wealthy family living in luxury in what could be one of the largest such villas in the country.

Finds include oysters which were artificially cultivated and then carried live from the coast in barrels of salt water, indicating how rich the family were.

The dig also turned up coins, brooches, bones of animals including a suckling pig, wild animals which had been hunted and a Roman well, while the experts identified a Roman child's coffin which had been holding geraniums by Mr Irwin's kitchen.

The villa - which is being compared to the Roman home at Chedworth, Gloucestershire, in size and wealth - was built sometime between 175 AD and 220 AD and was repeatedly remodelled up to the mid 4th century AD.

The dig also revealed occupation of the site dating back to a pre-Roman roundhouse.

And archaeologists found evidence of fifth-century pottery and timber structures within the partly ruined villa, suggesting the presence of a Romano-British family who did not have the resources to live in the house but remained at the site.

Mr Irwin said: "I was overwhelmed by the realisation that someone's lived on this site for 2,000 years.

"You look out at an empty field from your front door, and yet 1,500 years ago there was the biggest house, possibly, in all of Britain."

Dr David Roberts, Historic England archaeologist, said the find was very significant for a number of reasons.

All large Roman villas found in the UK were important, he said, while this villa's high state of preservation and the finds of material dating from the fifth century, a post-Roman but pre-Saxon period for the region, also made it significant.

"This site has not been touched since its collapse 1,400 years ago and, as such, is of enormous importance. Without question, this is a hugely valuable site in terms of research, with incredible potential," he said.

"The discovery of such an elaborate and extraordinarily well-preserved villa, undamaged by agriculture for over 1,500 years, is unparalleled in recent years," he said.

Asked how highly the site rated in terms of the digs he had seen in his career, Dr Roberts said: "Because I'm a Roman archaeologist, it rates very highly indeed.

"It's one of the best sites I have ever had the chance to work on."

There were still questions to be answered after the "small" excavation to see how well preserved the site was and its dates, including exactly how big the villa is, how the site relates to the Roman road and how it should be preserved, he said.