Treasure hunters have damaged a 1,900-year-old stretch of Hadrian’s Wall by digging illicitly for ancient artefacts, according to experts.

Historic England said a surge in “nighthawk” metal detectorists searching illegally for Roman loot under the cover of darkness had left more than 50 holes around Brunton Turret, one of the best preserved sections of Hadrian’s Wall in Northumberland, which was built by the 20th Legion of the Roman army.

The heritage body said the nighthawks were not only stealing ancient artefacts, but also damaging very vulnerable subterranean archaeological remains from the Roman frontier.

Mike Collins, Historic England’s inspector of ancient monuments at Hadrian’s Wall, said the vandals were robbing the public of the knowledge that could be gleaned from the ancient artefacts.

“We know that the majority of the metal detecting community complies with the laws and regulations regarding discovery and recovery of objects from the land,” said Collins.

“But the small number of people who steal artefacts and damage ancient sites are breaking the law and robbing us all of the knowledge and understanding that objects from the past can give us.

“These nighthawks are committing a criminal offence and we’d like everyone’s help to ensure they are caught. Together we can protect the precious shared legacy that our archaeological sites hold.”

Historic England said there had been a spate of nighthawking incidents at other sections of the wall over the past three years and that it was working with Northumbria police to identify the offenders.

The 73-mile (117km) wall stretches between Wallsend in North Tyneside and Bowness on Solway in Cumbria and has about 160 scheduled monuments, including Roman camps, forts and signal stations.

It is illegal to use a metal detector without authorisation on these sites. Historic England said anyone with information should contact Northumbria police.

Mark Harrison, head of heritage crime and policing advice for Historic England, said: “Illegal metal detecting is not a victimless crime. We may never see or fully understand the objects taken or damaged because they have been removed from their original sites with no care or record as to their history or context.”

“Historic England will continue to work with Northumbria police, the Crown Prosecution Service and the metal detecting community to identify the small criminal minority who are intent on causing loss and damage to our shared cultural heritage and to bring them to justice.”

