The oil, which appears to be black oil, currently affects an area of shoreline of less than 50m and there is a light sheen on the water.
There has been an oil spill in Tauranga Harbour.
A reporter at the scene said he could see patches of oil on the surface of the water, near Matapihi rail bridge.
Workers battled to beat the fading light in the oil clean-up. Photo / George Novak
Stephen Mellor, compliance manager at the Bay of Plenty Regional Council, said a call was received on the councilpollution hotline at 4pm Sunday to report oil on the beach at the far tip of Matapihi.
The oil, which appeared to be black oil, currently affects an area of shoreline of less than 50m and there is a light sheen on the water, Mellor said.
Staff were out attempting to clear as much of the oily debris as possible before it got dark, and would be back out at first light tomorrow assessing the scene and finishing any clean-up which was not possible tonight, Mellor said.
"We have responded with our pollution staff. We're manually picking up as much of the oil as we can and getting it into bags, so it ... won't go back basically into the harbour."
He said it was too early to tell what caused the spill or where the oil came from.
"We're taking notes, taking photographs, and cleaning up the oil," Mellor said.
Oil in the water near the Matapihi Rail Bridge. Photo / George Novak
"We will visually assess the amount of oil that we can see along the whole shoreline and what we can pick up, we will.
"But basically it's just a visual assessment and an estimation of how much. And then we'll go to an investigation phase of where it may have come from.
Workers clean up spilled oil at Tauranga Harbour. Photo / George Novak
"We're just rushing to do as much as we can with the failing light. And we'll come back at first light."
Workers clean up spilled oil at Tauranga Harbour. Photo / George Novak
Oil in the water near the Matapihi Rail Bridge. Photo / George Novak
Oil in the water near the Matapihi Rail Bridge. Photo / George Novak
If anyone notices any further areas of oil, they are encouraged to call the Bay of Plenty Regional Council's Pollution Hotline on 0800 884 883 to report it.
