Police are probing the unauthorised excavation of a Iron Age broch in the Western Isles – considered one of the best preserved examples of its type.

Dun Torcuill sits on an uninhabited island on a loch on North Uist dating back thousands of years.

Anyone convicted of the offence could face up to two years in jail.

A spokesperson for Historic Environment Scotland (HES) said: “Dun Torcuill is an archaeological site of national importance, and is protected as a scheduled monument.

“Unauthorised works on sites such as Dun Torcuill are illegal, and can seriously damage and disturb both upstanding and buried archaeological deposits.

“We would urge anyone with information regarding this incident to contact Police Scotland.”

Highlands and Islands MSP Donald Cameron added: “This news is deeply dismaying and I very much hope that those responsible are held to account.

“North Uist has a wealth of archaeological remains and we have a duty to do everything possible to ensure that they are safeguarded for the future.”

As a scheduled monument, Dun Torcuill is legally protected and recognised as being of national importance.

Officers are liaising with Historic Environment Scotland to establish the full circumstances.

The damage reported to police on October 22 is described as the clearance of tumbled stone from the site.

Sergeant Gavin McDevitt, of Lochmaddy Police Station, said: “Damaging or removing any part of a scheduled monument is a criminal offence.

“In this instance, there is the potential for destabilisation of the monument, and/or the loss of archaeological deposits previously protected by the tumbled stone.”

He added: “It is an offence under the Ancient Monuments and Archaeological Areas Act 1979 to undertake works without Scheduled Monument Consent.”

The penalties for offences under the Act are considerably higher than those for damage to property or vandalism offences, with fines ranging up to £50,000 or prison sentences of up to two years.

Sgt McDevitt added: “Police Scotland and HES are working closely to investigate this report and we are particularly keen to hear from anyone who has visited the monument within the last six months.”

Anyone with information is asked to contact police on 101.