A clean-up operation and investigation are under way after oil leaked into the River Thames in Grays on Thursday.

The Port of London Authority (PLA) sent a specialist oil response vessel to the river at Grays after a member of the public reported oil on the water.

A spokesman for the PLA said the oil had got into the river through a storm drain.

A boom has been placed around both the drain and the spill and efforts are being made to clear up the oil.

He described the incident as “comparatively small” and added: “Officers from the Environment Agency are investigating what caused the oil spill.”

The incident comes a day after a family of dolphins were spotted in the area.