Oil major BP said a well has been depressurised after a seepage of oil was detected on the Magnus field.
The company confirmed Transocean reported the incident when its rig the Paul B Lloyd Junior was completing work in the North Sea.
A spokeswoman for BP said: “We can confirm Transocean has reported a minor seepage of oil emanating from a wellhead in the Magnus field. The Transocean rig the Paul B Lloyd Junior was working on the well when the seepage was detected.
“The well has been depressurised and this has minimised any further release until the well can be sealed. The initial leak estimate is 48kg of oil.”