As much as 40,000-plus barrels of oil per day are pouring from BP's ruptured well in the Gulf of Mexico, a US official has said, more than doubling the previous government estimate.

"The lowest estimate that we're seeing that the scientists think is credible is probably about 20,000 barrels, and the highest that we're seeing is probably a little over 40,000," Marcia NcNutt, director of the US Geological Survey and chair of a US-government-led flow rate assessment team, told reporters yesterday.