Ancient coins discovered by a man with a metal detector have been auctioned for more than £35,000.

The 41 Celtic gold coins, dating back to the first half of the 1st century, were found by a mystery collector in a Kent field.

Morton and Eden auction house in London said one of the treasures broke records for a Celtic coin found in the UK.

The hoard fetched three times the expected price because many of the coins had been preserved in pristine condition, auctioneers said.

Morton and Eden said the precise location of the field is being kept secret to deter bounty hunters.

But a spokesman did disclose that the coins were found by a metal detector user over a three-year period between 2003 and 2006 near the town of Westerham.

The record-breaker was a gold stater which bears the name of an obscure ruler called Diras, thought to be from north of the Thames in an area governed by the Trinovantes and Catuvelauni tribes.

Only one other example is recorded, now in the British Museum. It sold to a New York dealer for £12,075, setting a new world auction record for a UK Celtic coin. It was estimated at between £3,000 and £4,000.

Coin factfile

# The 41 coins - each the size of a button - were remarkable because of their generally pristine condition.

# The hoard comprised three staters and 38 quarter staters, mostly depicting a “Celticized” horse surrounded by various motifs.

# Their designs were ultimately copied from earlier Greek coins and their usage came to an end when Claudius invaded Britain in 43 AD.

# The majority of the coins are attributed to the Cantii tribe which was centred in present-day Kent.