Queensland health authorities are working to track everyone who came into contact with a man who has died of diphtheria.
The 27-year-old was flown to Prince Charles Hospital on January 24, after being admitted to Cairns Hospital.
Cairns and Hinterland Hospital and Health Service confirmed on Thursday the man had died.
The Health Service has been locating those in contact with the man in an effort to trace the infection and prevent its spread.
The man has not recently travelled overseas, meaning the infection was caught in Australia.
It's understood the man was not vaccinated against the disease, which is extremely rare in Australia.
The Australian Medical Association Queensland said no vaccinated person had died from diphtheria in Australia in 20 years.
In 2011 an unvaccinated Brisbane woman also died from the disease after contracting it from a friend who had returned from overseas.
Diphtheria is caused by bacteria and results primarily in swelling in the nose, throat and windpipe, which can cause breathing difficulties.