“Nighthawks” armed with metal detectors are illegally raiding England’s most sensitive heritage sites and plundering booty, a report said on Monday.
English Heritage, the public body looking after sites such as Stonehenge, said thieves were using state-of-the-art equipment and information they shared online to find antiquities and sell them on the Internet.
The chances of detecting the so-called nighthawks were low and the penalties for being caught were light, it said in a report, the first study of its kind.
But it warned that while many stolen items were worth very little, valuable information about where they were found and their context could be lost forever.
“Responsible metal detecting provides a valuable record of history, but illegal activities bring responsible ones into disrepute,” said English Heritage chairman Barry Cunliffe.
“Nighthawkers, by hoarding the finds or selling them on without recording or provenance, are thieves of valuable archaeological knowledge that belongs to us all,” he said.
“Even in the case when the finds are retrieved, the context of how and where exactly the finds were found has been lost, significantly diminishing their historical value,” Cunliffe said.
He called for a national database to help track nighthawkers and their activities.
Nighthawking is the search and removal of antiquities from the ground using metal detectors without the permission of landowners or where the practice is banned.
English Heritage said 240 police reports of raids between 1995 and last year likely represented just a fraction of the crime, revealing that only one in seven landowners who knew they had been targeted had alerted the authorities.
About one in 20 archeological excavation sites were targeted, they said, with Roman sites a favorite.