Families living on Motiti Island, off the coast of Tauranga, won't touch food in their gardens or the sea for fear it may have been contaminated by an oil dispersant.
Concerns are being raised about the possible effects of the use of the dispersant Corexit 9500 in the early stages of the response to the Rena oil spill.
Maritime New Zealand (MNZ) trialled the dispersant for a week on heavy fuel oil that spilled from the Rena, but it proved to be ineffective in the conditions.
The use of Corexit 9500 was officially suspended on October 13 and it has not been used since.
However, local iwi want authorities to look more seriously at the concerns of Motiti Island residents.
Tauranga Moana and Te Moana A Toi Iwi Forum spokesman Charlie Tawhiao said some families worry they might get sick if they eat food gathered from the sea or their gardens.
"We will be formally asking the powers that be, including Maritime New Zealand and the public health authorities, to look more seriously into the concerns by getting independent experts to carry out more thorough and comprehensive tests," he said.
"Our people on the island are feeling like guinea pigs and they have every right to because this is the first time in our country's history that Corexit 9500 has been used to breakdown oil in the water."
A MNZ spokeswoman told NZ Newswire Corexit 9500 is one of the world's most heavily scrutinised dispersants and it is approved for use by the New Zealand government.
She said public health officials have no confirmed reports of anyone suffering illness that could be attributed to the use of dispersant in the Rena oil spill response.
The Bay of Plenty Regional Council is carrying out ongoing environmental tests to monitor any effect of Corexit 9500 in the water.
NZN