Four people died and 45 others needed hospital treatment after contracting the disease in June 2012.
Legal experts acting for the victims are being forced to raise court action to secure documents which they believe will assist them in identifying the likely source of the outbreak.
The Health and Safety Executive (HSE) carried out a review and submitted its findings to the Crown Office and Procurator Fiscal Service (COPFS) last year, however as yet the report has not been made available to the victims and their legal representatives.
Elaine Russell, a partner and expert in illness and injury claims at Irwin Mitchell Scotland, said: “It is simply not right that victims and the families of those who died still don’t know for sure what happened and authorities simply must provide answers urgently.
She added: “Files on the matter were passed to the Procurator Fiscal Service in February, but still there has been no further word on this matter. In order to try and move this forward, we are now embarking on court action to secure the release of vital documents.
“Two years is simply too long and it is time that the silence on this terrible ordeal is finally broken.”
Cooling towers in the south-west of Edinburgh have previously been identified as a possible source of the Legionella bacteria.
Legionnaires’ disease is a potentially fatal form of pneumonia and is caught by inhaling droplets of water, suspended in the air, containing harmful levels of Legionella bacteria. The bacteria is common in rivers and ponds but exposure is more likely from water systems such as cooling towers and spa pools.
Victims have suffered from respiratory problems and pains in the joints in their arms and legs and some sufferers have told of becoming so weak they struggled to walk up the stairs in their own home.
Lawyers at Irwin Mitchell Scotland say the continued silence from the Scottish Government and the Health and Safety Executive (HSE) regarding the outcome of investigations is ‘totally unacceptable’.
Elaine Russell added: “After the outbreak in Stoke, the source of illness was identified and communicated quickly allowing the victims to understand what happened and seek justice for their illness, but the lack of information on this Edinburgh outbreak remains a significant obstacle that has to be addressed. It is a pity that court action is required to get information.”