Published: May 20, 2010 6:02 PM EDT
Updated: May 20, 2010 6:01 PM EDT

COVINGTON, La. (AP) - BP says a mile-long tube it inserted into a leak on the blown-out well in the Gulf of Mexico is capturing 210,000 gallons of oil a day, but some is still escaping.

The company has long estimated that 210,000 gallons is the total amount that's leaking, but BP spokesman Mark Proegler said Thursday the tube is not sucking up all the oil. He would not estimate how much is not being captured.

Several professors who have watched video of the leak say they believe the amount is much higher than BP's estimate. The oil has been leaking since the offshore drilling rig Deepwater Horizon exploded and sank off Louisiana a month ago.

Heavy, sticky oil from the spill is starting to clog Louisiana marshes and some has reached a powerful current that could take it to Florida and beyond.