The National Museum of Scotland in Chambers Street, Edinburgh, is the third place to be served with an improvement notice by investigators.
The notice requires the museum to ensure that key staff members are appropriately trained in the management of water systems, which includes overseeing the ongoing monitoring and maintenance regime undertaken by specialist contractors.
The Improvement Notice relates solely to the training of staff and not to the operation of cooling towers.
The Scottish Health Secretary says there are 24 confirmed and 37 suspected cases of Legionnaires' disease. She expects this figure to rise.
Legionnaires' is a disease that strikes fear in people and its history shows it can be deadly.
The Scottish Health Secretary will today update MSPs on efforts to deal with a deadly outbreak of Legionnaires' disease in Edinburgh.