BP has closed down a major pipeline in Alaska after workers discovered a leak, calling to a halt almost all the oil production on Alaska's North slope, an area that produces 630,000 barrels a day.
The incident, which occurred last Saturday, is expected to drive up oil prices, a cost which could be passed on to motorists at the pumps.
A BP spokesman based in America described the leak as "a significant event" and it is not clear how long it will take to restart production.
Fuel prices have also risen recently due to expectations of supply constraints in the future, and this unexpected setback caused BP shares to slide nearly 2.5% this morning.
"From an engineering perspective, we would doubt that any shutdown will last more than two to three days," said P Morgan analyst Lawrence Eagles. "Government inspectors are likely to want a more comprehensive understanding of the cause, remedy and ways to prevent such leaks from occurring in the future. There is as yet no restart date, but we would not be surprised if a further week is added to the process."
Prudhoe Bay is America's largest oil reserve. BP is the largest shareholder in the company which runs the Trans-Alaska pipeline, called Alyeska Pipeline Service.
There have not been any reports of environmental damage because of the leak. Alyeska said yesterday that around 10 barrels of oil had been recovered from the basement of a booster pump room, and that around one barrel of oil remained.
BP Pipelines owns nearly 47% of Alyeska, with ConocoPhillips Transportation owning 28%, ExxonMobil Pipeline owning 20%, and smaller shareholders controlling the remainder.