Alert sounds as treasure hunters loot Yorkshire’s historic sites

English Heritage is investigating several reports of unauthorised metal detecting at protected ancient sites.

Eleven ancient monuments in Yorkshire have suffered damage in recent months, although treasure hunters known as “nighthawks” are not to blame for all the damage.

Nighthawks, who generally operate under cover of darkness with metal detectors and spades, have been blamed for damage at Mount Grace Priory at Northallerton, North Yorkshire.

Holes have been dug around the site by nighthawks who have targeted the historic site up to five times in recent months. The English Heritage site is England’s most important Carthusian ruin and dates back to 1398.

Last week English Heritage officers were told that more holes had been discovered and some of the damage is close to the ruined priory.

Investigations are also taking place into damage at other ancient monuments. Some have involved vandalism and others is damage caused by accident when water pipes or other services are being installed.

English Heritage officers are investigating incidents at the medieval town of Hedon and at Brough, both in East Yorkshire. A spokeswoman described the incidents as “unauthorised works” but he could not go into detail as prosecutions may follow.

One of the 11 ancient monuments, Whitby Abbey, recently saw some damage caused by water pipe laying in an area known as Donkey Fields.

English Heritage said consent had not been obtained during digging which unearthed medieval and 19th century remains.

“It would have been nice to have done the dig in more controlled circumstances,” said an English Heritage spokesman, adding: “Yorkshire Water and the contractors were very helpful – work was stopped and all parties tried to sort out what happened.”

A Yorkshire Water spokesman said there had been some confusion about obtaining consent and a mistake had been made.

Keith Emerick, an inspector of ancient monuments with English Heritage in Yorkshire, said he did not believe the recession had affected the number of incidents of nighthawking, although he said the authorities were now more aware of the issue.

Earlier this month English Heritage launched a crackdown on damage to the historic environment, teaming up with police and the Crown Prosecution Service.

It is thought the discovery of Anglo-Saxon gold in Staffordshire and Roman coins unearthed in Somerset may have led to more people metal detecting without permission.

A report in 2009 revealed that illegal metal detectoring was a problem Yorkshire, Lincolnshire, Norfolk, Suffolk, Essex, Kent and Oxfordshire.

The report’s authors received information that a lot of nighthawking was carried out by ex-miners who could be operating out of North Yorkshire or County Durham.

Battlefields were also being plundered, including the War of the Roses battle site at Towton, near Tadcaster.

The report said antiquities often ended up on internet auction sites, with little information about where they were from or how they were found.

Although nighthawks are motivated by making money, the authors said they had been told by nighthawks themselves “they justify the crime by relating it to class war, taking what is their common inheritance from the landowning class”.