The home of the Scottish Catholic Archives in Edinburgh has been closed to researchers and members of the public so that urgent conservation work can be carried out on its collection.
The immediate closure of Columba House came after mould was discovered on some items, the result of dampness in the main storage area in the sub-basement.
Reports from the last thirty years indicate this has been a recurring problem for the building, a 19th-century townhouse.
Columba House has been home to the Scottish Catholic Archives for over 50 years. The archive collections are the responsibility of the Trustees of the Scottish Catholic Heritage Collections Museum, commonly called the Blairs Museum, who have taken the decision after receiving reports from specialists in archive conservation and historic buildings.
The collections will be treated by a team of specialist conservators.
An arrangement was already in place before the discovery of mould for the University of Aberdeen to house the archives on long-term loan.
A spokesman for the Catholic Church said the transfer of the collections had gone from being "desirable" to "essential".
Archbishop Mario Conti, Chairman of the Trustees, said: "We have emphasised for some time that Columba House was not fit for purpose. The latest reports confirm this."
Further announcements will be made in the future as to when the archives are available again for study by scholars and members of the public.