An offshore North Sea oil rig has..

been partially evacuated on Friday after reports of an oil leak on board

Helicopters airlifted workers at around 10.30am from the Heather Alpha platform, about a hundred miles north east of the Shetland Islands.

Emergency services were responding to reports of a spillage on board, just before 9am.

A spokeswoman for Aberdeen Coastguard told Sky News there was no fire on board the platform, and the evacuation was precautionary.

A spokesman said the incident was dealt with "in-house" by the operators, and that no emergency rescue craft were involved.

Operator Petrofac confirmed it investigated reports of an incident and emergency procedures were activated.

No Coastguard or RAF assets were involved in the evacuation process.

The oil production platform is owned by Lundin and has operated since the discovery of the Heather field in the 1970s.

In a statement, Petrofac said the platform had been shut down following an "escape of oil".

The firm said: "There are 90 personnel on board and as a precaution 57 non-essential personnel have been de-manned by helicopter to Shetland.

"Three helicopters were mobilised to carry out this operation."