Devizes metal detectorist Dave Crisp has fulfilled a dream by finding one of the largest hoards of Roman coins in Britain.

Mr Crisp, 63, was staggered when he uncovered more than 52,000 coins in a huge pot buried in a field in Frome. The coins date back to the third century AD.

He said: "It's a find of a lifetime. I have been detecting for 22 years and I have had some nice finds but nothing like this."

Mr Crisp, of Waylands, found the coins in April after his metal detector gave a "funny signal."

He dug down about 18 inches and discovered the top of the pot. He pulled out some clay and a little Radial, a bronze Roman coin.

Mr Crisp reported the find to the authorities allowing archaeologists to excavate the site.

It took three days to excavate the site and on the first night Mr Crisp and his 17-year-old grandson, Aaron King, of Devizes, slept there on guard.

Mr Crisp said he was astounded by what the archaeologists found.

"When I found the coins I didn't know what size the pot was, I thought it would be small but it was more like a beer barrel," he said.

"I had seen hordes before but nothing like this. It was massive and it just got bigger and bigger. I was amazed."

Mr Crisp is secretary of Trowbridge Metal Detecting Club and goes detecting at least once a week. He has access to 15 sites across Wiltshire and Somerset with permission from the landowners.

The coins are likely to be declared treasure at an inquest in Somerset on July 22 and Mr Crisp will receive a reward after the coins are valued by experts from the British Museum. They are expected to be worth thousands of pounds.

Mr Crisp, a hospital chef, said whatever he received he would split the reward equally with the landowner.

He said: "Money's money. I'm more interested in the finds. At the end of the day you are saving history. Every time you dig up a Roman brooch or coin it's not disintegrating into the ground."

Mr Crisp is married with a daughter and three grandchildren. His wife, Shirley, a retired hospital cleaner, said: "He always said he would find a hoard."

Experts from the Portable Antiquities Scheme at the British Museum believe the coins were probably intended as some sort of religious offering by a community and that the coins were worth about four years' pay for a legionary soldier.

Some of the coins Mr Crisp found are on display in Gallery 68 at the British Museum until mid-August.

The story of the excavation will be featured in a BBC Two archaeology series, Digging for Britain, to be broadcast next month.