Ministers have announced plans to redefine the meaning of “treasure” in order to increase the protection of precious artefacts.
Items of treasure will no longer just be defined by their “material qualities”, it was announced on Friday.
Instead, the official definition will take into account an item’s historic and cultural significance.
Culture minister Caroline Dinenage said that artefacts will be better protected for the public under the new definition.
It is hoped the move will allow museums to acquire more objects of national importance for public collections.
Ms Dinenage said: “The search for buried treasures by budding detectorists has become more popular than ever before and many ancient artefacts now see the light of day in museums’ collections.
“However, it is important that we pursue plans to protect more of our precious history and make it easier for everyone to follow the treasure process.”
The new policies are not expected to be implemented until 2022.
Next year, a specialist research project will help develop the new definition with detectorists, archaeologists, museums, academics and curators all expected to contribute.
It comes after a public consultation and will be one of the biggest changes to the Treasure Act which came into effect nearly 25 years ago.
According to the current definition, objects are designated as treasure if they are more than 300 years old, made of gold or silver or found with artefacts made of precious metals.
If an object is identified as treasure, it becomes the property of the Crown and is available for acquisition by museums for public display.
However, this definition is no longer deemed appropriate with the growing popularity of metal detecting.
An increasing number of finds from Roman Britain have been found since the Act was passed that do not meet treasure criteria because they are often made from materials such as bronze.
A spectacular Roman helmet, known as the Crosby Garrett helmet, was discovered by an amateur metal detectorist in Cumbria in 2010 which sparked a fundraising campaign to try to keep it on public display.
However, because it was made of a copper alloy it did not fit the legal definition of treasure and sold at Christie’s auction house for £2.3 million.
Other finds include a bronze-enamelled horse brooch from between the second and fourth century AD whose finder allowed to go on display.
Similarly, a rare Roman figurine wearing a cloak known as the Birrus Brittanicus was discovered near Chelmsford in 2014. A delay in the sale meant Chelmsford City Museum were able to raise the funds to purchase the figurine to display for the local community.
Michael Lewis, Head of Portable Antiquities Scheme and Treasure at the British Museum, said: “We very much welcome working with the DCMS as it takes forward its work to reform Treasure law to protect our shared heritage and encourage best practice amongst finders.”