A rare hoard of Roman coins has been found in Bath at the site of a new city centre hotel.

Around 150 coins have so far been unearthed in the run-up to work on the new Gainsborough Hotel and Thermal Spa.

But the Lower Borough Walls site is expected to yield more than 1,000 coins once the whole haul has been examined.

The find has been greeted with excitement by archaeologists because some of the coins are thought to date from the middle of the third century, one of the most poorly represented periods for coins in Britain.

The coins were discovered by Cotswold Archaeology while excavating the area around the site of the main pool of the new spa hotel, which is being created by Bath-based businessman Trevor Osborne.

Richard Sermon, head of archaeology for Bath and North East Somerset Council, said: "The coins give us a great insight into the Roman monetary system, and provide a glimpse of life in third century Bath, a time of political and economic crisis throughout the Roman Empire.

"The hoard reveals that the citizens of Aquae Sulis (the Roman name for Bath) were no different from people today - hiding their money under the mattress or floor boards."

Under the Treasure Act the find has been reported to the Avon coroner - who will decide on its ownership.

The copper and silver coins are described as being in mixed condition, with some stuck together as a result of corrosion.

But two of the best preserved coins have been provisionally identified as Antoniniani, used during the earlier and middle years of the third century AD.

One appears to be an issue of the emperor Phillip I, and was deposited against the inside face of a masonry wall in what is believed to be a small, oval pit, dug through the floor of a Roman building.

The coins would originally have been stored in leather or cloth bags.

Andrew Ryan, director of Bath Hotel and Spa Ltd, developers of the new hotel said: "We are delighted that such an important find has been made after extensive archaeological investigations on the site of the new Gainsborough Hotel. We hope that the discovery of the coins will further enhance knowledge of the history of Bath."