Personnel are understood to be returning to a North Sea oil rig after a security threat earlier today.

A 23-year-old British woman was taken ashore by police as part of the inquiry.

The security threat could have been a hoax but is not considered terrorism related.

Hundreds of oil workers were evacuated from the oil rig in the North Sea off Scotland

UK Royal Air Force helicopters, together with police, undertook an operation to remove over 500 people from the North Sea oil rig.

The Safe Scandinavia, which is 282 kms northeast of Aberdeen, is an accommodation rig or 'flotel' for workers.

The evacuation operation followed an apparent bomb threat.