Marine officials in the Cook Islands looking for the cause of illnesses at Titikaveka lagoon, say seaweed may be the culprit.
The Ministry of Marine Resources says a Cook Islander studying environmental science in Hawaii has indicated a dark green variety of seaweed may be producing an irritant to the eyes, nose and throat.
The acting Secretary of Marine Resources, Ian Bertram says there are similarities between problems at Titikaveka and an outbreak of eye and respiratory irritation in Hawaii.
Nearly 90 cases of irritation were recorded at Lahaina on Maui, in August 1983.
Scientists at New Zealand's Cawthron institute have been sent water samples to be tested for traces of the seaweed.
Officials in the Cooks have drawn comparisons with the Hawaii incident and are tracing similarities in symptoms.
The head of the government taskforce investigating Titikaveka, Don Beer, says New Zealand scientists have also helped to identify the seaweed as an irritant.
"Yes it is a breakthrough for us, but I must also add that the expert, Dr Charles Eason and Dr Virginia Hope also pointed to this particular seaweed. We'll be collecting samples of the seaweed over the next couple of days, and they'll be sent to the Cawthron Institute in Nelson for testing."