NEW ORLEANS — BP conceded today that more oil than it estimated is gushing into the Gulf of Mexico as heavy crude washed into Louisiana's wetlands for the first time, feeding worries and uncertainty about the massive monthlong spill.

Mark Proegler, a spokesman for oil giant BP PLC, said a mile-long tube inserted into a leaking pipe over the weekend is capturing 210,000 gallons a day — the total amount the company and the Coast Guard have estimated is gushing into the sea — but some is still escaping. He would not say how much.

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

Proegler said the 210,000 gallons — 5,000 barrels — has always been just an estimate because there is no way to measure how much is spilling from the seafloor.