THE region’s hidden heritage is under threat from clandestine “nighthawks” who venture out in the dark to search for buried artefacts from the past.

Illegal metal detecting – known as “nighthawking” – is regarded as the theft of valuable archaeological knowledge that belongs to everyone.

And a national survey carried out by English Heritage has revealed that the Yorkshire region is the worst affected part of the country.

The Nighthawking Survey, published today, unearthed reports of illegal metal detecting at least 30 sites in the region between 1995 and last year.

But the real figure could be much higher as secrecy surrounding the crime means that it is significantly underreported.

But the penalties when caught are usually only small fines – and now calls are being made to toughen up the laws and the setting up of a central database.

The report highlights two Roman sites near Catterick, North Yorkshire, and praises the constructive way in which the problem was tackled.

The Roman town of Cataractonium – Catterick – and a nearby roadside settlement at Bainesse were repeatedly targeted by nighthawks.

But local metal detector enthusiasts, with landowner support, linked up with English Heritage and North Yorkshire County Heritage Unit to jointly undertake archaeological investigations.

A wealth of new information was gleaned, reinforcing the sites’ importance, and adding to an earlier evaluation carried out in advance of a proposed A1 road upgrade.

The report concluded that by involving legitimate metal detectorists, further nighthawk activity had probably been reduced.

English Heritage’s inspector for ancient monuments, Neil Redfern, said: “Quite apart from the fact that nighthawking is illegal, it also causes untold damage to our heritage.

“By removing an object from the ground without proper recording you take away its context, which can tells us so much about its age, purpose and significance.”

He added: “The heart of the problem lies in the vicious circle of under-reporting. This creates a false picture of the seriousness of the situation, making this a low priority crime for the police.

It is also compounded by the difficulty in collecting evidence.”