A coach driver discovered Britains largest hoard of Bronze Age axeheads while waiting for a party of school-children at a Dorset farm.

Tom Peirce, 60, asked the farms owner if he could use his metal detector in one of the fields during his lunchbreak. Within minutes he heard a loud beep and found part of a bronze axe.

Over the next three days Mr Peirce and two other metal detectorists unearthed more than 500 items of Bronze Age metalwork, including 268 complete axeheads. The axes, buried at three separate locations more than 50 metres apart, could be worth tens of thousands of pounds, which Mr Peirce would share with the farms owner, Alfie OConnell.

Axeheads were used as a form of currency during the Bronze Age, about 3,000 years ago, but some experts believe that the hoard may have had some ritual significance such as an an offering to the gods.

Mr Peirce, from Ringwood, Hamp-shire, who has been metal-detecting for five years, said: When we took them out of the ground some of them were so pristine you would think you had just bought them at B&Q yet they were 3,000 years old.

We were very lucky because there was not much else in the field. If we had tried another place or walked in a different direction wed never have found them. This was a once in a lifetime find.

Mr OConnell, 62, who has owned the farm near Swanage for four years, said: Within about half-an-hour of Tom searching he came rushing over to me looking shocked. During the war a plane had crashed in the same field and for a minute I thought he had found a bomb. We went back up there on my tractor and saw the axeheads. I didnt have a clue what they were. I thought it was scrap metal at first. It is very exciting.

The axeheads, which are four inches long and two inches wide, are being assessed by the British Museum, which may buy them.

The coroner for Bournemouth, Poole and East Dorset will hold an inquest at which it is expected that the axeheads will be declared treasure-trove. If so, the landowner and finder would receive a reward reflecting the market value of the hoard.

Andrew Fitzpatrick, of Wessex Archaeology, has been asked by the British Museum to look for signs of a settlement. He said: The artefacts could have been used as a form of currency and buried at a time of crisis but many people believe they were buried as an offering to the gods.

A lot of Bronze Age objects like this were buried in the ground and it is a bit of a coincidence that many people didnt go back for them.