4 November 2011 Last updated at 09:14 ET

Gas work at Shell Gannet Alpha leak pipeline completed

Shell's Gannet Alpha platform was the focus of the incident in August

Work to release gas trapped in a pipeline which spilled more than 200 tonnes of oil into the North Sea has been completed, Shell has said.

Divers earlier closed a relief valve after the incident at the Gannet Alpha platform in August.

Shell said the latest operation on the 4km structure had "further enhanced its stability and security".

Plans are being made to deal with the remaining oil in the pipeline. An investigation into the leak is ongoing.

The impact of the oil spill in the North Sea was minimal, Scottish Fisheries Minister Richard Lochhead said in September.

The leak was discovered about 300ft (91m) below the surface.

The Gannet Alpha oil platform is 113 miles (180km) off Aberdeen.