Oil is seen gushing from the broken pipe rising out of the top of the wellhead more than 1,500 metres below the water's surface in the Gulf of Mexico. (BP)The Obama administration is asking BP to disclose more information to the public about the massive oil spill in the Gulf of Mexico, including measurements of the size of the leak as well as air quality.

Press secretary Robert Gibbs said Thursday that the White House is writing to BP to ask it to post that information on its website and to be more transparent in its response.

The move came after BP conceded that more oil than estimated is gushing into the Gulf and a live video feed was posted online showing a large plume of oil spewing next to a tube carrying some of it to a tanker on the surface.

The video was posted on the website of the U.S. select committee on energy independence and global warming after Representative Ed Markey, a Democrat from Massachusetts, and other legislators pushed BP to make it available to the public.

"What you see are real-time images of a real-world disaster unfolding 5,000 feet below the surface of the Gulf," Markey said. "These videos stand as a scalding, blistering indictment of BP's inattention to the scope and size of the greatest environmental catastrophe in the history of the United States."

Louisiana Gov. Bobby Jindal points to a map where oil from the Deepwater Horizon oil spill has been spotted in the coastal wetlands of Louisiana on Wednesday. (David Quinn/Associated Press)

BP spokesman Mark Proegler said a 1.6-kilometre tube inserted into a leaking pipe over the weekend is capturing 800,000 litres a day — the total amount BP and the U.S. Coast Guard had estimated is gushing into the sea — but some is still escaping. He wouldn't say how much.

Several experts who have watched video of the leak said they believe the amount spewing out is much higher than official estimates.

Proegler said the 800,000-litre figure has always been just an estimate, because there is no way to measure how much is spilling from the sea floor.

"I would encourage people to take a look at the changing amount of oil coming from the ocean floor," said Steve Rinehart, another BP spokesman. "It's pretty clear that now that we're taking 5,000 barrels of oil a day, there's a significant change in the flow reaching the sea."

The well blew out a month ago after an explosion on the offshore drilling rig Deepwater Horizon killed 11 people, sank the rig and broke a riser pipe attached to the wellhead.

Oil reaches Louisiana wetlands

The state governor's office confirmed Wednesday that thick, dark oil has seeped into Louisiana's wetlands.

Oil from the Gulf of Mexico spill is seen seeping into the marshes at Pass a Loutre, La., on Wednesday. (Gerald Herbert/Associated Press)

"The oil is here," Gov. Bobby Jindal said. "It is on our shores and in our marsh."

Thin traces of the oil spill were first reported in the state's wetlands on April 29, about a week after oil was found to be leaking from the well.

"The oil is no longer just a projection or miles from our shore," Jindal said. More than 54 kilometres of shoreline in nine coastal areas have been affected, he said.

The area is home to hundreds of species of fish, birds and other wildlife along the Gulf Coast, one of the world's richest seafood grounds, teeming with shrimp, oysters and other marine life.

The spill has already crippled Louisiana's seafood industry. With $1.8 billion in annual sales, it's the largest industry of its kind in the lower 48 states.

Jindal has asked the U.S. Army Corps of Engineers to approve a plan to build a wall of sand, or "sand booms," along the shore to protect it from the oil. He has also authorized workers to fill gaps along the coastline with sand bags and inflatable dams called Tiger Dams.

With files from The Associated Press