Oil giant Shell is battling an oil leak in a North Sea pipeline off the British coast, a company spokesman for the Anglo-Dutch company said Friday.\"We have discovered a leak in a flow line between a well and a production platform\" in the North Sea, Wim van de Wiel told AFP in The Hague. He said the leak was discovered Wednesday after an oil sheen was spotted on the surface near the Gannet Alpha production platform, around 180 kilometres (113 miles) east of Aberdeen.A remotely operated submarine was sent to investigate and the well was shut down shortly afterwards to take the pressure off the pipeline, Van de Wiel said. He added a ship with oil containment equipment on board as well as a plane were deployed to the area.He said Shell was keeping a close eye on the situation with \"our main focus being environmental safety,\" adding the company had notified the relevant British authorities. It was not immediately clear how much oil had leaked into the sea, Van de Wiel added.