Samples of the oil found along the Taranaki shore are being sent to Australia so the source of the spill can be found.
Taranaki Regional Council workers had been cleaning up the shore near Okato Beach since Tuesday.
Taranaki Regional Council director of resource management Fred McLay said6cu m of oil-contaminated sand had been collected and would be disposed of at a landfill.
Green Party co-leader Jeanette Fitzsimons said the spill should ring alarm bells in Government about the potential risks of oil exploration.
"The Taranaki contamination should be taken as wake-up call about what could happen on a far bigger scale, in a much more environmentally sensitive region in our southern oceans," she said.
Maritime New Zealand's Marine Pollution Response Service (MPRS) arrived in Taranaki this morning and is helping to clean the spill and identify it's origins.
MPRS general manager Nick Quinn said the environmental impact of the spill would be minimal.
Until the oil type was identified, it was hard to begin the elimination process of possible sources, Mr Quinn said.
"Once the oil type has been confirmed, a trajectory mapping system would be able to provide more accurate data on the likely location of the oil spill, and when it occurred.
"Each type of oil has characteristics that influence its behaviour when spilled."
Two offshore platforms had given oil samples which had been sent to Australia for urgent analysis, Mr Quinn said.
The Taranaki Regional Council response team undertake regular oil spill training with Auckland based MPRS.
"It's times like these where the hours upon hours of training really does pay off," he said.
