About 50,000 Roman and Celtic coins, which date from the 1st Century BC, were found by two metal detector enthusiasts (Reg Mead and Richard Miles) in Jersey, U.S.. Though their ownership is unclear, the coins will now be separated and cleaned at the Jersey Archive. Dr Philip de Jersey, a former Celtic coin expert at Oxford University, said the haul was "extremely exciting and very significant".

The expert also said that each individual coin was worth between £100 and £200, raising this large coin hoard worth up to £10 million.

The exact number of coins found has not been established, but archaeologists said the hoard weighed about three quarters of a tonne and could contain about 50,000 coins.

The exact location of the hoard has not been revealed by the authorities but Environment Minister, Deputy Rob Duhamel, said he would do everything he could to protect the site. "Sites like these do need protection because there is speculation there might even be more," he said. "It is a very exciting piece of news and perhaps harks back to our cultural heritage in terms of finance. It was found under a hedge so perhaps this is an early example of hedge fund trading."

It is the first hoard of coins found in the island for more than 60 years. Several hoards of Celtic coins have been found in Jersey before but the largest was in 1935 at La Marquanderie when more than 11,000 were discovered.

Dr de Jersey said it would take months for archaeologists to find out the full value of the haul. He said: "It is extremely exciting and very significant. It will add a huge amount of new information, not just about the coins themselves but the people who were using them."