A Waiheke Island environmental group says several samples of marine life taken from the Hauraki Gulf have tested positive for the rat poisons brodifacoum and 1080.

Sarah Silverstar of Ocean Aware says the samples of marine birds, oysters and dog vomit, taken from Waiheke and Rangitoto Islands, were tested in an Auckland clinic by EAV machine and all were found to contain brodifacoum and, to a lesser degree, 1080.

A woman who had become mildly ill after eating local snapper the week before also tested positive for brodifacoum, said Silverstar.

The Department of Conservation dropped 147 tonnes of brodifacoum bait on Rangitoto and Motutapu Islands last month.

A spate of marine animals dying and dogs becoming ill after playing on Auckland beaches led many people to suspect brodifacoum was the culprit.

But DoC, in alliance with Auckland Regional Public Health, MAF Biosecurity, Auckland Regional Council and North Shore and Auckland City Councils, says independent scientists have carried out extensive testings and determined none of the deaths were caused by brodifacoum.

DoC spokeswoman Nicola Vallance said the department offered to have independent scientists test Silverstar's samples, but she declined and had them tested at a private clinic by EAV machine.

"We are very aware of people's concerns and have gone to great lengths to get testing done by New Zealand's leading scientists," said Vallance.