Local media reported that this was the first death caused by a jellyfish sting in 15 years.
Queensland police confirmed to CNN on Thursday that they were preparing a report for the coroner following the sudden death of the 17-year-old from Bamaga.
The boy was transported to the hospital on 22 February after the incident and died on 1 March, police said.
A spokesman for the Royal Flying Doctor Service, an air medical service in Australia, told CNN in a statement that the crew stabilized the patient in Bamaga before transferring him to Townsville Hospital on February 22.
Named after their body shape, box jellyfish have tentacles covered by small poison-laden darts, known as nematocysts.
The Australian variety of the creature has a body size that can reach up to 30 meters in diameter and tentacles that can grow up to 3 meters in length.
“The recent incident in Bamaga is a timely warning to take precautions when swimming in the sea in any northern water,” Marlow Coates, Torres and Cape Hospital and Health Service said in a statement.
“We are seeing sightings of both box jellyfish and jellyfish that cause Irukandji syndrome in our waters,” he said.
Coates said swimmers should wear protective clothing, such as lycra or neoprene suits, and stay out of the water if they don’t have protective gear.
The authorities added that a large Chironex sting is “immediate and terribly painful” and “should be considered life threatening”.