Canterbury Regional Council says an oil spill on a Timaru beach has been contained.
It was estimated 10 to 20 litres of oil were discharged from a stormwater outlet at Pātītī Point early Wednesday afternoon.
Southern Zone lead Gina Slee said the council launched an immediate response.
"[Our incident response team] applied special oil-absorbing and water-repelling pads to soak up the oil from the surface of the water and booms were in place overnight.
"We have also taken water samples, which will be analysed to determine the type of hydrocarbon present, which helps inform the likely environmental impact and assist with our investigation."
The discharge had since stopped but residue may still be visible.
There was no evidence to suggest the spill reached the sea, Slee said.
"We are now focused on the clean-up and reducing any impact to the environment. Our team is also investigating what caused the spill, working closely with Timaru District Council."
The beach and walkway were open as usual today, with the public asked to stay away from the small area being cleaned up.