Fears of a leak on the Statfjord B North Sea field have been raised after a bump appeared on the seabed.
An error was first spotted in a well on the sea in June, Aftenbladet reports.
Subsea investigations of the Statoil-operated field, in the Norwegian North Sea, have now found a raised lump on the seabed three feet high and nine feet wide, suggesting a leak beneath the ground.
“We have initiated an in-depth study of this event,” spokesman Oliver Heradstveit told Aftenbladet.
“It will not be ready until the end of October.”