Yet another scientist on the government-assembled group estimating flow rates has spoken up and voiced skepticism about BP's claims.

Steve Wereley, a Purdue University engineering professor and a member of the Flow Rate Technical Group, criticized BP for mischaracterizing how much oil it is capturing with its containment cap, according to The Associated Press.

Current estimates are that the cap is currently capturing 630,000 gallons per day -- that's 15,000 barrels of oil. The official estimate of the overall leak is between 12,000 and 19,000 barrels a day. Wereley told the AP that it's more likely that between 19,000 and 43,000 barrels of oil have been spewing into the Gulf daily. From the AP:

"BP is claiming they're capturing the majority of the flow, which I think is going to be proven wrong in short order," Wereley said. "Why don't they show the American public the before-and-after shots?"

He added: "It's strictly an estimation, and they are portraying it as fact."

As we pointed out yesterday, Ira Leifer, another member of the Flow Rate Technical Group, expressed frustration earlier this week over what he perceived as BP's stonewalling their efforts to get a better estimate.

"It's apparent that BP is playing games with us," Leifer told The New York Times. He spoke in agreement with his teammate on BP's claims about its containment efforts.

"I do not know how BP can make that assertion when they don't know how much oil is escaping," Leifer told MSNBC.

Messages left for BP both yesterday and today have not been returned.