Unlawful metal detectorists are being warned after reports of people stealing from Hadrian’s Wall.

Police have teamed up with Historic England, the organisation responsible for protecting the country’s historical sites, to try and stamp out the over-keen detectorists.

The landmark - which is a UNESCO World Heritage Site - stretches 73 miles from coast to coast and was built to guard the north west border of the Roman Empire.

Warning signs have now been put up at Corbridge, the Roman fort and town, which forms part of Hadrian’s Wall.

It is hoped the signs will build awareness and help put an end to this form of criminal activity.

Mike Collins, Historic England’s inspector of ancient monuments for Hadrian’s Wall, said: “Most people who go metal detecting comply with the law and the codes of practice for responsible metal detecting, but there’s a small but significant element – known as ‘nighthawks’ - who are damaging and stealing parts of this internationally important historical site.

“Essentially, they are robbing us all of parts of our national heritage as the artefacts they take or destroy could have added to our knowledge of Roman Britain.

“Illegal metal detecting at Hadrian’s Wall is particularly a problem at this time of year as adjacent farmland is being cropped and ploughed, making it easier for criminals to access and steal historic artefacts.”

PC Lee Davison, from Northumbria Police, said: “Protecting those historic sites is very much a partnership effort and it saddens us that they can often attract criminal activity.

“It may be the case that many people aren’t even aware they are committing a criminal offence but we hope we can work closely with Historic England to educate the public.

“We will be conducting patrols to deter criminal behaviour and if we identify anyone who has been stealing historic artefacts then they will be arrested.”

Illegal metal detecting should be reported to police by calling 101.