Oil and gas producer OMV New Zealand is concerned there have been two spills from the same permanently moored tanker off the Taranaki coast in a month.
An oil processing and storage tanker at the Maari oil field, which OMV New Zealand operates, had a spill on 18 October and another on Saturday.
Last week, the company organised a clean-up of blobs of oil spotted on beaches along the Kapiti Coast in case it was Maari oil.
Test results to determine the source of the oil are due next week.
