The 40-year-old is being treated at the Victoria Hospital in Kirkcaldy, where she was said to be "very seriously ill".

Health officials in the region say they are investigating the cause of the infection.

The woman was taken to the Victoria Hospital

The woman, who has not been named, fell ill on 20 November.

She was admitted to the Victoria Hospital a week later with chest problems.

However, she was transferred to the hospital's intensive care unit this week after it was confirmed that she suffering from Legionnaires' disease.

Dr Charles Saunders, consultant in Public Health Medicine at Fife NHS Board, said: "We are working closely with Fife Council's environmental health department to look into possible sources of infection.

Water droplets

"While this will take a little time to complete, initial investigations have revealed no obvious source of the infection.

"We are not aware of any other cases of Legionnaires' disease linked to this one."

Legionnaire's disease is spread by bacteria in tiny water droplets, typically from air conditioning systems.

Between 30 and 40 cases are reported in Scotland each year.