Bay of Plenty Regional Council oil spill response staff have been working to contain an oil spill at Sulphur Point in Tauranga.
An estimated 2000 litres of oily sludge is believed to have been discharged from a tanker truck about 5pm Monday as it was removing the sludge from a vessel. Some of this sludge entered the water.
Council staff used booms and other spill equipment to contain the spill as much as possible.
For safety reasons, they had to halt clean-up activities for the night shortly but will recommence at first light.
Regional on-scene commander Adrian Heays said while it appeared most of the oil has been contained underneath the wharf, staff won't know until first light whether any has managed to get past the booms and further into the harbour.