Gloucestershire County Council says a hoard of 2,000-year-old silver coins found in a field is “very rare indeed”.
The authority had not commented on the discovery of the Roman coins after they were found off the A40 near Gloucester by Cinderford metal detector enthusiast Susan Hurrell.
She was sure the eight coins, dating from 134BC to 37AD, would be classed as treasure and said it had been the find of a lifetime for her.
Now the council has backed her view.
A spokesman for its archaeology service said: “This is a very interesting hoard of republican coins to have been found in Gloucestershire. These sort of coins can be found in Roman coin hoards of the early empire right up until AD 200.
“To find a hoard that consists of solely republican coins is very rare indeed. The quality of the coins are all rather worn except for the latest example which is dated AD 14-37 so it is quite possible that this hoard may have been lost after the Roman conquest of 43 AD.
“This is a treasure find and as a result has been reported to the coroner.”
Mrs Hurrell has said she wants to keep the treasure, even if she has to pay the farmer whose land she found the coins on, some money.
The council said that if a museum had shown an interest in having the coins, they would have been valued but it said that interest had not been forthcoming and so the find would be returned to Mrs Hurrell.