Oil giant BP has shut down its oil platform located 75 kilometres west of the Shetland Islands.
In a statement the firm said, a quantity of oil in water was released into the sea from the Clair platform yesterday morning.
It was due to a technical issue with the system designed to separate the mixed production fluids of water, oil and gas, the company added.
The leak was stopped within an hour once the issue was identified. BP is investigating the cause of the technical issue and the field will remain offline until the investigation is concluded.
They have been working alongside BEIS to assess any potential environmental impacts and to agree the best way to respond.
The firm added: “At present, we believe the most appropriate response is to allow the oil to disperse naturally at sea, but contingencies for other action are being prepared.
“Oil has been observed on the sea surface and we are monitoring its movement. Both direct observation and oil spill modelling indicate the oil to be moving in a northerly direction away from land. The total oil in water volume that was released has yet to be accurately assessed and work to determine this is ongoing.”