New law redefines treasure trove

The new Treasure Act comes into force today replacing common- law precedents and practices dating back to the time of Richard the Lionheart.

Metal detector users are the main target. The country's 30,000 "detectorists" find most of the hundreds of thousands of ancient artefacts unearthed each year. But archaeologists worry that the portable past has not been properly protected or recorded.

The Act sets out a new definition of "treasure" - notably objects at least 300 years old containing a substantial amount of gold or silver, and hoards of coins. All finds must be reported within 14 days. Anyone failing to report a discovery risks a pounds 5,000 fine, three months in jail or both.

When a museum wishes to acquire an item declared treasure by a coroner, the finder will be paid a reward based on market value. In one of Britain's most lucrative finds, the Hoxne Hoard, discovered in Suffolk in 1992, a value of pounds 1.75m was agreed. The 15,000 Roman coins and jewellery went to the British Museum.

The Act does away with the absurdity that an object could only be declared treasure trove - technically the property of the monarch - if it had been deliberately buried with the intention of recovery. This set a coroner's jury the tricky task of divining whether someone in the Middle Ages was trying to evade taxes or simply careless.

Mark Fisher, the arts minister, said the Act would ensure more items were properly recorded. Metal detector users have felt victimised by the legislation, but he said that "far from curtailing their activities", the Act would remove confusion.