Jay Ngwele resigned from his role on Wednesday as Climate Change Special Envoy in protest over the way disaster relief funding was spent on travel costs for politicians to meet with victims.
Mr Ngwele said his people were sent back to Ambae too quickly and without adequate support or services.
He said despite reassurances from authorities that the water was safe to drink once boiled, independent tests from 12 different sites on the west of Ambae have shown the water is contaminated.
