The Council is working with Historic England to stop any further unauthorised work being done at Grade II listed Tonedale House and Grade II* listed Tonedale Mill in Wellington.
The interior of Tonedale House has been stripped out and the council believes that the former boiler room at the mill could be torn down and the hugely important historic machinery ripped out and sold.
The complex, which has planning consent for conversion into flats, forms part of the historic Fox Bros woollen mills.
The buildings are historically and architecturally important and listing helps to protect them for present and future generations to enjoy. Listed Building Consent must be applied for if changes are to be made to a listed building.
The Council is investigating if any works have been carried out to the boiler room and machinery. It is considering prosecution for unauthorised works carried out to date and the serving of an injunction to prevent any further loss of historic significance to the buildings.
A meeting with representatives from the developers is taking place today when the council is making its position clear and asking what measures will be taken to rectify what has been done.
Leader of the Council, Councillor John Williams, said: “I am horrified at what’s taken place. Wellington’s industrial heritage is nationally significant and needs to be properly protected. I sincerely hope that we do not have to resort to legal action – but we will not hesitate to do so if circumstances demand that we do.”
John Ette, Principal Advisor for Historic England in the South West, said: “Grade II* listed Tonedale Mill is one of the most important mill complexes in the South West and Historic England has been working with Taunton Deane Borough Council to secure the preservation of the site. We are very concerned about the unauthorised works and support the actions of the council in safeguarding the mill and its contents.”