Police are investigating a “substantial theft” of stone from a subterranean room in a medieval castle.

Yester Castle in East Lothian, which has an underground hall known as “Goblin Ha'”, has been closed to the public due to safety concerns following the theft.

The castle, a ruin, is legally protected as a nationally important monument under the provisions of the Ancient Monuments and Archaeological Areas Act 1979.

Police Scotland said the theft of the stone has created a large area of damage in the wall that supports the vault of the underground room, which has caused concerns around safety, and the castle has been closed to the public for the foreseeable future.

On Friday the force issued an appeal for information about the theft.

It said: “Offences under the Act include works without consent and damage, including adding to or removing from the monument. Breaches of the Act can carry penalties of up to six months imprisonment or fines of up to £50,000.

“Police Scotland are appealing to members of the public to come forward with any information regarding the theft and suspicious vehicles that may have been near the castle and surrounding area since the end of July 2021.

“If you have any information regarding this please call 101 quoting incident number 1181 of October 12.”

Yester Castle and the Goblin Ha’ belonged to the Gifford family in the 12th-14th centuries.

An entry on Canmore, the online catalogue of the National Record of the Historic Environment, states the Goblin Ha’ may date from the 13th century.

The site featured as a fort during Haddington’s occupation in the 16th century before being abandoned as a residence after the Reformation.