A child from the NSW north coast may be the third person linked to the recent Splendour In The Grass festival to contract meningococcal disease.
Earlier this month a Sydney man in his 40s who had attended the festival died with the disease.
NSW Health has urged anyone who attended Splendour In The Grass - which took place from July 21-24 at the North Byron Parklands - to be alert to symptoms of the potentially fatal disease.
Anyone showing symptoms - which can include a red or purple rash, fever, headache, stiffness, light sensitivity, nausea, diarrhoea, drowsiness and confusion - are urged to contact a doctor immediately.
Although the diseases is uncommon it can be fatal, with authorities warning it can develop very quickly and kill within hours.
A Northern Territory man in his 30s died with meningococcal on Friday, while a two-year-old child with the diseases died in rural South Australia in July.
Health authorities in the territory said the man had undertaken no recent interstate or international travel.