Five companies face charges under the Health and Safety at Work Act following an outbreak of Legionnaires disease in Edinburgh.

The outbreak in 2012 saw four people die and 92 cases identified. The source of the outbreak was never identified and the Crown ruled at the time there was no evidence to justify any prosecution.

The charges are connected to alleged breaches of health and safety regulations and are unrelated to the deaths.

North British Distillery, Macfarlan Smith, Ashland Industries, Pera Services and Chemtech Consultancy are accused of exposing people to the risk of legionnaires between 2009 and 2013.

It is alleged the companies failed to ensure the safety of employees and members of the public from the risk of exposure to legionella bacteria from cooling towers at property in Wheatfield Road.

At the city’s Sheriff Court legal representatives of the companies pleaded not guilty to the indictment.

Sheriff Alison Stirling was told the trial could last up to 12 weeks. A further hearing will be held on 25 January next year. No date has been set for the trial.