Five days after he took delivery of a metal detector and seven steps into his first treasure hunt, a novice archaeologist has helped to rewrite Scottish history and may be a millionaire after he unearthed four 2,300-year-old torcs made of pure gold a few feet from his parked car.

David Booth, a game warden at Blair Drummond Safari Park, in Stirlingshire, bought his £240 detector from a website that claimed “treasure need not be an idle dream”. What then seemed an absurd sales puff has proved strangely prophetic. The hoard he discovered at the edge of a field was described yesterday as “prime Iron Age bling” by one leading archaeologist and is conservatively valued at £500,000, rising to £1.5 million.

Mr Booth, 35, said there was a “sense of disbelief” about his discovery. “I saw a glimpse of one of them, then uncovered the rest of the hoard. They were in a wee group. Half me was saying, ‘that does look important’, but I was thinking I couldn’t be that lucky on my first go.

“I took them home, gave them a wee clean up and went online. I looked at some torcs and kind of guessed this was iron age history.”

He guessed correctly. Mr Booth’s find, made on September 29, is the most significant discovery of Iron Age metalwork in Scotland and is said to be of international significance.

The hoard comprises four necklaces, all dating from the 3rd century BC. Two ribbon torcs, in perfect condition, are relatively simple in design and represent a local style of jewellery made from a twisted ribbon of gold. A third, broken item is half of an ornate torc of southern French origin, probably from the Toulouse area and the only one of its kind found in Britain.

Finest of all is a unique, braided gold wire torc, a remarkable hybrid of Mediterranean craftsmanship and more traditional Iron Age motifs. This might have been made by a craftsman for a local chieftain, according to Dr Fraser Hunter, of the National Museum of Scotland. If so, it would suggest unexpectedly strong links between Scotland and Southern Europe, three centuries before the Roman invasion.

Dr Hunter said that the torcs had originally been buried beneath a circular building, which may have had religious significance. Finds of this type are usually either votive offerings to the gods, or items that had been hidden in time of war.

After taking delivery of his detector, Mr Booth practised for an hour in the kitchen and garden at his home on the Blair Drummond estate. Then he identified a promising local field from his knowledge of history and sought the landowner’s permission for a treasure hunt. The rest was a matter of driving up in his Ford Focus, on his day off, and testing his equipment before embarking on his first search.

His brand of metal detector, a basic model, is able to distinguish between iron, silver and gold, but a signal registering gold does not necessarily mean that its owner has struck it rich. More often than not, the find will be a spent shotgun cartridge.

“I parked up and got the metal detector out,” he recalled. “There was an area of flat ground behind the car, and I thought, I’ll just scan this first, before I head out into the field. Literally about seven steps behind where I had parked, I found them.”

Mr Booth dug down six inches and claimed his prize. His next move was to e-mail a picture of his find to the Treasure Trove Unit, at the National Museums of Scotland, an independent body that acts for the Queen and the Lord Treasurer’s Remembrancer.

Within three hours of opening the e-mail, a team of archaeologists had arrived on site, and the field had been closed down to potential souvenir hunters. Even now, after a five-week sweep of the area, security-conscious staff at the museum refer only to a site “in Stirlingshire”.

Dr David Caldwell, of the Scottish Treasure Trove Unit, praised the “exemplary” actions of Mr Booth following his discovery. “Invariably the reward would be equal to the market value and it goes to the finder,” Dr Caldwell said. “The landowner has no right at all, but in practice most metal detectorists make a deal with landowners before they start searching that they will go 50/50.”

One million pounds would be lovely, Mr Booth says, but he already feels “honoured” to have made the discovery. He hopes to have paid off his Ford Focus by spring.

What lies beneath

In 1881 Alexander Graham Bell used an early metal detector to try to locate an assassin’s bullet lodged in the chest of American President James Garfield. Bell failed when the metal bed on which Garfield was lying confused the detector

Modern metal detectors owe their origin to Gerhard Fisher, who noted how ore-bearing rocks distorted radio signals. He suggested that if a radio beam could be distorted by metal, then it should be possible to design a machine that would detect metal using a search coil resonating at a radio frequency

During the Second World War Lieutenant Josef Stanislaw Kosacki, a Polish officer attached to a unit stationed in St Andrews, developed Fisher’s ideas into a practical mine detector. His design was used to clear German minefields at the second battle of El Alamein and later in the invasion of Normandy. Wartime secrecy meant that Stanislaw’s work was not made public for more than 50 years

David Booth’s find came five days after Terry Herbert had found 1,500 gold and silver pieces from the 7th century with his metal detector in a Staffordshire field

Father and son metal detectorists David and Andrew Whelan unearthed a gold and silver Viking cup near Harrogate, Yorkshire, in 2007. The cup contained 617 silver coins and jewellery, valued at more than £1.2 million

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