Gas transporters Gassco confirmed that engineers had found the mine last month, lying about ten metres from Europipe 2, just west of the Vestre Bokn island in Rogaland.
"The mine was first discovered by a submarine that was calibrating equipment along the pipe," Gassco communications director Kjell Larsen told Petro.no. "They saw a foreign object."
Gas and oil producers Statoil confirmed that the object was found at a depth of 240 metres. A remote-controlled submarine vehicle was sent back down to take pictures of the objects, with image analysis revealing it could be a German mine.
Analysts from the Norwegian Armed Forces said it was unlikely the 1-metre diametre mine posed a threat, but as it could contain up to 300 kilogrammes of explosives, all precautions will be made when removing it, probably in August.