A leak on a North Sea platform has forced the closure of a major pipeline system supplying UK oil, it has emerged.
The Brent pipeline system, which services up to 27 oil fields, was shut after oil was detected in one of the legs of the Cormorant Alpha platform off Shetland.
Workers have been airlifted off the rig as a technical team investigates.
Platform operator TAQA said yesterday the installation and all pipeline infrastructure had been shut as a precaution.
The Brent has been closed and eight other platforms in the area have had to cease production, the Press and Journal reported, stopping the flow of 90,000 barrels a day.
Oil transported through the Brent is said to represent between 5% and 6% of the UK's North Sea oil and gas production.
Professor Alex Kemp, an oil economist at Aberdeen University, said the closure would have a limited impact on oil prices.
He told BBC Radio Scotland's Good Morning Scotland programme: "What we have is an incident which impacts on the Brent pricing system which is used as a marker price for a lot of the world's production.
"If it continues one would expect a limited affect on the Brent price.
"But the Brent price doesn't just depend on Brent production, it depends on production from a lot of other fields.
"The effect should be limited because although the Brent price is the marker for a huge volume of oil in the world market, Brent production constitutes not all that big a proportion of the total."
A TAQA spokeswoman said arrangements were made for 92 people to be taken off the Cormorant Alpha, 94 miles from Lerwick, yesterday.
A statement from TAQA said: "Our number one priority is the safety and well-being of our people.
"We have stopped all non-essential work on the platform to focus all our efforts on addressing this issue."
Of the 90,000 barrels a day handled by the Cormorant Alpha, 42,600 are produced by Abu Dhabi energy company TAQA, which took over the platform in 2009.
Scotland's Energy Minister, Fergus Ewing, said: "The Scottish Government, including Marine Scotland, are monitoring this situation closely. No release of hydrocarbons has been reported and all non-essential staff on the platform have been safely removed.
"The Brent pipeline represents 6% to 7% of UK supplies and this does not impact security of supply at this time.
"The Health and Safety Executive are investigating and will determine when the pipeline system can be opened again, subject to any relevant safety measures being put in place."