He has discovered a second huge plume of oil in the Gulf of Mexico, 75 miles northwest of the leaking BP well, a Louisiana scientist claimed on Friday.

The Washington Post has reported that James R. Cowan Jr., a Louisiana State University professor, said his crew found globs of oil by sending a remotely controlled submarine about 400 feet below the surface.

His discovery a day after other scientists said they had found another vast plume of oil that stretched for miles east of the source of the leak, Cowan has reported.

Cowan further said that the newly discovered plume contains oil so thick, it covered the lights on the submarine, which resurfaced entirely black.

He said, "It almost looks like big wet snowflakes, but they're brown and black and oily."

It became impossible to determine how wide the plume was because the submarine traveled for miles from side to side and never found an end to the oil, he further added.

The Post also said that scientists say they worry the oil could move under the surface instead of floating, making it more difficult to contain, but BP officials have played down the threat.

Officials and Louisiana scientists say they have found thick oil on the shores.

USF Professor David Hollander had said on Thursday that scientists on a University of South Florida research vessel found dissolved oil east of the leak. The oil spread about 6 miles wide and extended 3,200 feet beneath the surface. (With Inputs from Agencies)