REPAIRS to a road in an East Lothian town have led to the discovery of a unrecorded mineshaft lying deep underground.

An inspection uncovered the ancient mineshaft in Prestonpans which has baffled experts as there are no records of how deep or how old the mine workings are.

Mining for coal in and around Prestonpans dates back to the 13th century, but there are no clues about the age of the mystery mineshaft under the B1631 road which runs through the town.

The Coal Authority, which is a non-departmental public agency of the UK Government, has stepped in to remediate the mine workings “to ensure the safety of road users and the local community”, according to a statement from the authority.

Many mines in past centuries have abandoned shafts that are a potential hazard, especially when they are unrecorded – the authority is to hold a seminar on the problem in Scotland next month.

The Prestonpans mineshaft is a particular problem because it runs underneath a gas main.

Michael Owens, from the Coal Authority’s Public Safety and Subsidence Team, said: This is an unrecorded coal mine shaft, meaning we hold no records of the depth, location or any specific information regarding the previous treatment method.

“The mine shaft is located under a road which has live services beneath, including a medium pressure gas main that will need to be isolated and supported during works.

“This coupled with the close proximity to a Category B-listed wall and protected trees, meant we’ve had to co-ordinate our efforts alongside various stakeholders to design a suitable solution.

He continued: “The permanent safety solution is to excavate and cast a reinforced concrete cap over the position of the suspected unrecorded, rectangular coal mine shaft.

“The reinforced concrete cap will be constructed to withstand all traffic.

“It is inevitable that when an unrecorded mine shaft is discovered, the local community will be inconvenienced. The Coal Authority sincerely apologises for this disruption.”