Shell said it has a remote-controlled vehicle searching for the leak in the North Sea, off the Scottish Coast [Reuters]

Royal Dutch Shell PLC says it is trying to stop oil leaking from a flow line at one of its drilling platforms in the North Sea off the coast of Scotland.

Spokesman David Williams confirmed on Friday that the leak was on-going but stopped short of specifying how much oil may have escaped.

Shell could not provide further details on the spillage, but says it knows which line contained the leak and the flow has been stemmed as the underwater well has been shut in and the line at the Gannet Alpha platform is being de-pressurised.

The global oil and gas company, which is headquartered in the Netherlands, said it has a remote-controlled vehicle searching for the leak.

Meanwhile, a plane is monitoring the surface, and a vessel with cleanup equipment and dispersant was on standby.

Gannet is located 180 km east of Aberdeen, Scotland where Shell operates the platform along with partner Exxon Mobil Corp.'s UK unit Esso.

The platform had 10 leak incidents in 2009 and 2010, according to an HSE document showing voluntarily declared spills.

The Maritime and Coastguard agency said it was aware of the incident and that its "counter-pollution and salvage officer" was monitoring the situation.

The health and safety executive said it was making enquiries into the incident.

The situation is different from BP's devastating spill last year in the Gulf of Mexico where the actual well was not contained and pressure had built up.

Source: Agencies